gas: x86: fix code comments and other nits

ChangeLog: * gas/config/tc-i386.c
gas: x86: ginsn: adapt the APX insn handling
2025-11-16 12:34:43 +00:00 · 2024-03-28 16:55:50 -07:00 · 2024-03-28 16:55:50 -07:00 · 2024-03-28 16:55:50 -07:00 · 2024-03-28 16:55:50 -07:00 · 2024-03-28 16:55:50 -07:00
55 changed files with 3004 additions and 131 deletions
--- a/gas/config/tc-aarch64.c
+++ b/gas/config/tc-aarch64.c
@@ -37,6 +37,7 @@

 #include "dw2gencfi.h"
 #include "dwarf2dbg.h"
+#include "scfi.h"

 #define streq(a, b)	      (strcmp (a, b) == 0)

@@ -6062,6 +6063,725 @@ get_aarch64_insn (char *buf)
  return result;
 }

+#ifdef OBJ_ELF
+
+/* DWARF register number for R1.  Used as dummy value when wzr.  */
+#define GINSN_DW2_REGNUM_R1_DUMMY 1
+
+bool
+aarch64_scfi_callee_saved_p (uint32_t dw2reg_num)
+{
+  if (dw2reg_num == REG_SP /* x31.  */
+      || dw2reg_num == REG_FP /* x29.  */
+      || dw2reg_num == REG_LR /* x30.  */
+      || (dw2reg_num >= 19 && dw2reg_num <= 28) /* x19 - x28.  */)
+    return true;
+
+  return false;
+}
+
+/* Get the DWARF register number for the given OPND.
+   Whether 31 is used to encode WZR or SP is specified via SP_ALLOWED_P.
+
+   The caller must decide the value of SP_ALLOWED_P based on the instruction
+   encoding.  */
+
+static uint32_t
+ginsn_dw2_regnum (aarch64_opnd_info *opnd, bool sp_allowed_p)
+{
+  /* For registers of our interest (callee-saved regs, SP, FP, LR),
+     DWARF register number is the same as AArch64 register number.  */
+  if (!sp_allowed_p && opnd->reg.regno == REG_SP)
+    return GINSN_DW2_REGNUM_R1_DUMMY;
+
+  return opnd->reg.regno;
+}
+
+static ginsnS *
+aarch64_ginsn_addsub_imm (const symbolS *insn_end_sym)
+{
+  ginsnS *ginsn = NULL;
+  bool add_p, sub_p;
+  int32_t src_imm = 0;
+  uint32_t dst_reg, opnd_reg;
+  aarch64_opnd_info *dst, *opnd;
+
+  aarch64_inst *base = &inst.base;
+  const aarch64_opcode *opcode = base->opcode;
+
+  add_p = (opcode->opcode == 0x11000000);
+  sub_p = (opcode->opcode == 0x51000000);
+  gas_assert (add_p || sub_p);
+
+  gas_assert (aarch64_num_of_operands (opcode) == 3);
+  dst = &base->operands[0];
+  opnd = &base->operands[1];
+
+  dst_reg = ginsn_dw2_regnum (dst, true);
+
+  if (aarch64_gas_internal_fixup_p () && inst.reloc.exp.X_op == O_constant)
+    src_imm = inst.reloc.exp.X_add_number;
+  /* For any other relocation type, e.g., in add reg, reg, symbol, skip now and
+     handle via aarch64_ginsn_unhandled () code path.  */
+  else if (inst.reloc.type != BFD_RELOC_UNUSED)
+    return ginsn;
+  /* FIXME - verify the understanding and remove assert.  */
+  else
+    gas_assert (0);
+
+  opnd_reg = ginsn_dw2_regnum (opnd, true);
+
+  if (sub_p)
+    ginsn = ginsn_new_sub (insn_end_sym, true,
+			   GINSN_SRC_REG, opnd_reg, 0,
+			   GINSN_SRC_IMM, 0, src_imm,
+			   GINSN_DST_REG, dst_reg, 0);
+  else
+    ginsn = ginsn_new_add (insn_end_sym, true,
+			   GINSN_SRC_REG, opnd_reg, 0,
+			   GINSN_SRC_IMM, 0, src_imm,
+			   GINSN_DST_REG, dst_reg, 0);
+
+  ginsn_set_where (ginsn);
+
+  return ginsn;
+}
+
+static ginsnS *
+aarch64_ginsn_addsub (const symbolS *insn_end_sym)
+{
+  ginsnS *ginsn = NULL;
+  bool add_p, sub_p;
+  uint32_t dst_reg, src1_reg, src2_reg;
+  aarch64_opnd_info *dst, *src1, *src2;
+  ginsnS *(*ginsn_func) (const symbolS *, bool,
+			 enum ginsn_src_type, unsigned int, offsetT,
+			 enum ginsn_src_type, unsigned int, offsetT,
+			 enum ginsn_dst_type, unsigned int, offsetT);
+
+  aarch64_inst *base = &inst.base;
+  const aarch64_opcode *opcode = base->opcode;
+
+  add_p = (opcode->opcode == 0x0b200000);
+  sub_p = (opcode->opcode == 0x4b200000);
+  gas_assert (add_p || sub_p);
+  ginsn_func = add_p ? ginsn_new_add : ginsn_new_sub;
+
+  gas_assert (aarch64_num_of_operands (opcode) == 3);
+  dst = &base->operands[0];
+  src1 = &base->operands[1];
+  src2 = &base->operands[2];
+
+  dst_reg = ginsn_dw2_regnum (dst, true);
+  src1_reg = ginsn_dw2_regnum (src1, true);
+  src2_reg = ginsn_dw2_regnum (src2, false);
+
+  ginsn = ginsn_func (insn_end_sym, true,
+		      GINSN_SRC_REG, src1_reg, 0,
+		      GINSN_SRC_REG, src2_reg, 0,
+		      GINSN_DST_REG, dst_reg, 0);
+  ginsn_set_where (ginsn);
+
+  return ginsn;
+}
+
+/* Handle the load pair and store pair instructions.  */
+
+static ginsnS *
+aarch64_ginsn_ldstp (const symbolS *insn_end_sym, bool store_p)
+{
+  ginsnS *ginsn = NULL;
+  ginsnS *ginsn_ind = NULL;
+  ginsnS *ginsn_mem1 = NULL;
+  ginsnS *ginsn_mem2 = NULL;
+  uint32_t opnd_reg, addr_reg;
+  int32_t offset, mem_offset;
+  unsigned int width = 8;
+
+  aarch64_opnd_info *opnd1, *opnd2, *addr;
+  aarch64_inst *base = &inst.base;
+  const aarch64_opcode *opcode = base->opcode;
+
+  /* This function is for handling ldp / stp ops only.  */
+  gas_assert (opcode->iclass == ldstpair_indexed
+	      || opcode->iclass == ldstpair_off);
+  gas_assert (aarch64_num_of_operands (opcode) == 3);
+
+  opnd1 = &base->operands[0];
+  opnd2 = &base->operands[1];
+  addr = &base->operands[2];
+
+  addr_reg = ginsn_dw2_regnum (addr, true);
+  gas_assert (!addr->addr.offset.is_reg);
+  mem_offset = addr->addr.offset.imm;
+  if (opnd1->qualifier == AARCH64_OPND_QLF_W)
+    width = 4;
+
+  /* Handle address calculation.  */
+  if ((addr->addr.preind || addr->addr.postind) && addr->addr.writeback)
+    {
+      /* Pre-indexed store, e.g., stp x29, x30, [sp, -128]!
+	 Pre-indexed addressing is like offset addressing, except that
+	 the base pointer is updated as a result of the instruction.
+
+	 Post-indexed store, e.g., stp     x29, x30, [sp],128
+	 Post-index addressing is useful for popping off the stack.  The
+	 instruction loads the value from the location pointed at by the stack
+	 pointer, and then moves the stack pointer on to the next full location
+	 in the stack.  */
+      ginsn_ind = ginsn_new_add (insn_end_sym, false,
+				 GINSN_SRC_REG, addr_reg, 0,
+				 GINSN_SRC_IMM, 0, mem_offset,
+				 GINSN_DST_REG, addr_reg, 0);
+      ginsn_set_where (ginsn_ind);
+    }
+
+  /* Save / restore of floating point registers is not of interest for SCFI.
+     However, the address processing component may have updated the stack
+     pointer.  At least, emit that ginsn and return.
+     TBD_GINSN_GEN_NOT_SCFI.  */
+  if (aarch64_get_operand_class (opnd1->type) != AARCH64_OPND_CLASS_INT_REG)
+    return ginsn_ind;
+
+  /* With post-index addressing, the value is loaded from the
+     address in the base pointer, and then the pointer is updated.
+     With pre-index addressing, the addr computation has already
+     been explicitly done.  */
+  offset = mem_offset;
+  if ((addr->addr.postind || addr->addr.preind) && addr->addr.writeback)
+    offset = 0;
+
+  opnd_reg = ginsn_dw2_regnum (opnd1, false);
+  if (store_p)
+    {
+      ginsn_mem1 = ginsn_new_store (insn_end_sym, false,
+				    GINSN_SRC_REG, opnd_reg,
+				    GINSN_DST_INDIRECT, addr_reg, offset);
+      ginsn_set_where (ginsn_mem1);
+
+      opnd_reg = ginsn_dw2_regnum (opnd2, false);
+      ginsn_mem2 = ginsn_new_store (insn_end_sym, false,
+				    GINSN_SRC_REG, opnd_reg,
+				    GINSN_DST_INDIRECT, addr_reg, offset + width);
+      ginsn_set_where (ginsn_mem2);
+    }
+  else
+    {
+      opnd_reg = ginsn_dw2_regnum (opnd1, false);
+      ginsn_mem1 = ginsn_new_load (insn_end_sym, false,
+				   GINSN_SRC_INDIRECT, addr_reg, offset,
+				   GINSN_DST_REG, opnd_reg);
+      ginsn_set_where (ginsn_mem1);
+
+      opnd_reg = ginsn_dw2_regnum (opnd2, false);
+      ginsn_mem2 = ginsn_new_load (insn_end_sym, false,
+				   GINSN_SRC_INDIRECT, addr_reg, offset + width,
+				   GINSN_DST_REG, opnd_reg);
+      ginsn_set_where (ginsn_mem2);
+    }
+
+  /* Link the list of ginsns created.  */
+  if (addr->addr.preind && addr->addr.writeback)
+    gas_assert (!ginsn_link_next (ginsn_ind, ginsn_mem1));
+
+  gas_assert (!ginsn_link_next (ginsn_mem1, ginsn_mem2));
+
+  if (addr->addr.postind && addr->addr.writeback)
+    gas_assert (!ginsn_link_next (ginsn_mem2, ginsn_ind));
+
+  /* Make note of the first instruction in the list.  */
+  ginsn = (addr->addr.preind && addr->addr.writeback) ? ginsn_ind : ginsn_mem1;
+  return ginsn;
+}
+
+static ginsnS *
+aarch64_ginsn_ldstr (const symbolS *insn_end_sym, bool store_p)
+{
+  ginsnS *ginsn = NULL;
+  ginsnS *ginsn_ind = NULL;
+  ginsnS *ginsn_mem = NULL;
+  uint32_t opnd_reg, addr_reg;
+  int32_t offset = 0;
+  int32_t mem_offset = 0;
+
+  aarch64_opnd_info *opnd1, *addr;
+  aarch64_inst *base = &inst.base;
+  const aarch64_opcode *opcode = base->opcode;
+
+  /* This function is for handling ldr, str ops only.  */
+  gas_assert (opcode->iclass == ldst_imm9 || opcode->iclass == ldst_pos);
+  gas_assert (aarch64_num_of_operands (opcode) == 2);
+
+  opnd1 = &base->operands[0];
+  addr = &base->operands[1];
+
+  addr_reg = ginsn_dw2_regnum (addr, true);
+
+  /* STR <Xt>, [<Xn|SP>, (<Wm>|<Xm>){, <extend> {<amount>}}].
+     LDR <Xt>, [<Xn|SP>], #<simm>.  */
+  opnd_reg = ginsn_dw2_regnum (opnd1, false);
+
+  /* If opnd_reg is WZR, ignore this (OK to do for SCFI).  Note, this is a
+     potential case of TBD_GINSN_GEN_NOT_SCFI.  */
+  if (opnd_reg == REG_SP)
+    return ginsn;
+
+  if (aarch64_gas_internal_fixup_p () && inst.reloc.exp.X_op == O_constant)
+    mem_offset = inst.reloc.exp.X_add_number;
+  else
+    {
+      gas_assert (!addr->addr.offset.is_reg);
+      mem_offset = addr->addr.offset.imm;
+    }
+
+  /* Handle address calculation.  */
+  if ((addr->addr.preind || addr->addr.postind) && addr->addr.writeback)
+    {
+      ginsn_ind = ginsn_new_add (insn_end_sym, false,
+				 GINSN_SRC_REG, addr_reg, 0,
+				 GINSN_SRC_IMM, 0, mem_offset,
+				 GINSN_DST_REG, addr_reg, 0);
+      ginsn_set_where (ginsn_ind);
+    }
+
+  /* Save / restore of floating point registers is not of interest for SCFI.
+     However, the address processing component may have updated the stack
+     pointer.  At least, emit that ginsn and return.
+     TBD_GINSN_GEN_NOT_SCFI.  */
+  if (aarch64_get_operand_class (opnd1->type) != AARCH64_OPND_CLASS_INT_REG)
+    return ginsn_ind;
+
+  /* With post-index addressing, the value is loaded from the
+     address in the base pointer, and then the pointer is updated.
+     With pre-index addressing, the addr computation has already
+     been explicitly done.  */
+  offset = mem_offset;
+  if ((addr->addr.postind || addr->addr.preind) && addr->addr.writeback)
+    offset = 0;
+
+  if (store_p)
+    ginsn_mem = ginsn_new_store (insn_end_sym, false,
+				 GINSN_SRC_REG, opnd_reg,
+				 GINSN_DST_INDIRECT, addr_reg, offset);
+  else
+    ginsn_mem = ginsn_new_load (insn_end_sym, false,
+				GINSN_SRC_INDIRECT, addr_reg, offset,
+				GINSN_DST_REG, opnd_reg);
+  ginsn_set_where (ginsn_mem);
+
+  if (addr->addr.preind && addr->addr.writeback)
+    gas_assert (!ginsn_link_next (ginsn_ind, ginsn_mem));
+  else if (addr->addr.postind && addr->addr.writeback)
+    gas_assert (!ginsn_link_next (ginsn_mem, ginsn_ind));
+
+  /* Make note of the first instruction in the list.  */
+  ginsn = (addr->addr.preind && addr->addr.writeback) ? ginsn_ind : ginsn_mem;
+
+  return ginsn;
+}
+
+static ginsnS *
+aarch64_ginsn_jump (const symbolS *insn_end_sym)
+{
+  ginsnS *ginsn = NULL;
+  const symbolS *src_symbol = NULL;
+  enum ginsn_src_type src_type = GINSN_SRC_UNKNOWN;
+  uint32_t src_value = 0;
+  bool call_p = false;
+
+  aarch64_inst *base = &inst.base;
+  const aarch64_opcode *opcode = base->opcode;
+
+  if (opcode->iclass == branch_imm)
+    {
+      /* opcode 0x14000000 or 0x94000000.  */
+      gas_assert (inst.reloc.type == BFD_RELOC_AARCH64_CALL26
+		  || inst.reloc.type == BFD_RELOC_AARCH64_JUMP26);
+      src_symbol = inst.reloc.exp.X_add_symbol;
+      src_type = GINSN_SRC_SYMBOL;
+    }
+  else if (opcode->opcode == 0xd61f0000 || opcode->opcode == 0xd63f0000)
+    {
+      src_type = GINSN_SRC_REG;
+      src_value = ginsn_dw2_regnum (&base->operands[0], false);
+    }
+
+  if (opcode->opcode == 0x94000000 || opcode->opcode == 0xd63f0000)
+    call_p = true;
+
+  gas_assert (src_type != GINSN_SRC_UNKNOWN);
+
+  if (call_p)
+    ginsn = ginsn_new_call (insn_end_sym, true,
+			   src_type, src_value, src_symbol);
+  else
+    ginsn = ginsn_new_jump (insn_end_sym, true,
+			    src_type, src_value, src_symbol);
+  ginsn_set_where (ginsn);
+
+  return ginsn;
+}
+
+static ginsnS *
+aarch64_ginsn_jump_cond (const symbolS *insn_end_sym)
+{
+  ginsnS *ginsn = NULL;
+  const symbolS *src_symbol;
+  enum ginsn_src_type src_type = GINSN_SRC_SYMBOL;
+
+  aarch64_inst *base = &inst.base;
+  const aarch64_opcode *opcode = base->opcode;
+  aarch64_insn opc = opcode->opcode;
+
+  gas_assert ((opc == 0x34000000 || opc == 0x35000000
+	       || opc == 0x36000000 || opc == 0x37000000)
+	      || (opc >= 0x54000000 && opc <= 0x5400000d));
+
+  gas_assert (inst.reloc.type == BFD_RELOC_AARCH64_BRANCH19
+	      || inst.reloc.type == BFD_RELOC_AARCH64_TSTBR14);
+  src_symbol = inst.reloc.exp.X_add_symbol;
+
+  ginsn = ginsn_new_jump_cond (insn_end_sym, true,
+			       src_type, 0, src_symbol);
+  ginsn_set_where (ginsn);
+
+  return ginsn;
+}
+
+static ginsnS *
+aarch64_ginsn_mov (const symbolS *insn_end_sym)
+{
+  ginsnS *ginsn = NULL;
+  uint32_t src_reg = 0, dst_reg;
+  aarch64_opnd_info *src, *dst;
+  offsetT src_imm = 0;
+  enum ginsn_src_type src_type;
+
+  aarch64_inst *base = &inst.base;
+  const aarch64_opcode *opcode = base->opcode;
+
+  gas_assert (aarch64_num_of_operands (opcode) == 2);
+
+  dst = &base->operands[0];
+  src = &base->operands[1];
+
+  dst_reg = ginsn_dw2_regnum (dst, true);
+
+  if (src->type == AARCH64_OPND_IMM_MOV
+      && aarch64_gas_internal_fixup_p () && inst.reloc.exp.X_op == O_constant)
+    {
+      src_imm = inst.reloc.exp.X_add_number;
+      src_type = GINSN_SRC_IMM;
+    }
+  else
+    {
+      /* mov   x27, sp.  */
+      src_reg = ginsn_dw2_regnum (src, true);
+      src_type = GINSN_SRC_REG;
+    }
+
+  ginsn = ginsn_new_mov (insn_end_sym, false,
+			 src_type, src_reg, src_imm,
+			 GINSN_DST_REG, dst_reg, 0);
+  ginsn_set_where (ginsn);
+
+  return ginsn;
+}
+
+/* Check if an instruction is whitelisted.
+
+   An instruction is a candidate for whitelisting if not generating ginsn
+   for it, does not affect SCFI correctness.  */
+
+static bool
+aarch64_ginsn_safe_to_skip_p (void)
+{
+  bool skip_p = false;
+  aarch64_opnd_info *opnd = NULL;
+  uint32_t opnd_reg;
+
+  aarch64_inst *base = &inst.base;
+  const aarch64_opcode *opcode = base->opcode;
+  int num_opnds = aarch64_num_of_operands (opcode);
+  aarch64_opnd_info *addr = &base->operands[num_opnds - 1];
+
+  /* It is not expected to have reg offset based ld/st ops to be used
+     for reg save and restore operations.  Warn the user though.  */
+  if (opcode->iclass == ldst_regoff)
+    {
+      opnd = &base->operands[0];
+      opnd_reg = ginsn_dw2_regnum (opnd, false);
+      if (aarch64_scfi_callee_saved_p (opnd_reg))
+	{
+	  skip_p = true;
+	  as_warn ("SCFI: ignored probable save/restore op with reg offset");
+	}
+    }
+
+  switch (opcode->opcode)
+    {
+      /* Load/store FP register pair (offset) are safe to skip even if the base
+	 register is SP-based because there cannot be writeback with pre- or
+	 post- indexing.  */
+    case 0x2d000000: /* ldstpair_off.  Store FP register pair (offset).  */
+    case 0x2d400000: /* ldstpair_off.  Load FP register pair (offset).  */
+    case 0x3d000000: /* ldst_pos.  Store FP register (unsigned immediate).  */
+    case 0x3d400000: /* ldst_pos.  Load FP register (unsigned immediate).  */
+      /* IIUC, there cannot be a writeback here.  Confirm? FIXME.
+	if not true, need to generate addr gen opcodes at the least.  */
+      gas_assert (!addr->addr.writeback);
+      skip_p = true;
+      break;
+    default:
+      break;
+    }
+
+  return skip_p;
+}
+
+#define AARCH64_GINSN_UNHANDLED_NONE        0
+#define AARCH64_GINSN_UNHANDLED_DEST_REG    1
+#define AARCH64_GINSN_UNHANDLED_CFG         2
+#define AARCH64_GINSN_UNHANDLED_STACKOP     3
+#define AARCH64_GINSN_UNHANDLED_UNEXPECTED  4
+
+/* Check the input insn for its impact on the correctness of the synthesized
+   CFI.  Returns an error code to the caller.  */
+
+static int
+aarch64_ginsn_unhandled (void)
+{
+  int err = AARCH64_GINSN_UNHANDLED_NONE;
+  aarch64_inst *base = &inst.base;
+  const aarch64_opcode *opcode = base->opcode;
+  aarch64_opnd_info *dest = &base->operands[0];
+  int num_opnds = aarch64_num_of_operands (opcode);
+  aarch64_opnd_info *addr;
+  unsigned int dw2_regnum;
+  uint32_t addr_reg;
+  bool sp_allowed_p = false;
+
+  /* All change of flow instructions are important for SCFI.  */
+  if (opcode->iclass == condbranch
+      || opcode->iclass == compbranch
+      || opcode->iclass == testbranch
+      || opcode->iclass == branch_imm
+      || opcode->iclass == branch_reg)
+    err = AARCH64_GINSN_UNHANDLED_CFG;
+  /* Also, any memory instructions that may involve an update to the stack
+     pointer.  Some classes can be skipped altogether though, as they cannot be
+     used to push or pop stack because of disallowed writeback:
+      - ldst_unscaled, ldst_regoff, ldst_unpriv, ldstexcl, loadlit,
+     ldstnapair_offs.  FIXME double-check.   */
+  else if (opcode->iclass == ldstpair_off
+	   || opcode->iclass == ldstpair_indexed
+	   || opcode->iclass == ldst_imm9
+	   || opcode->iclass == ldst_imm10
+	   || opcode->iclass == ldst_pos)
+    {
+      addr = &base->operands[num_opnds - 1];
+      addr_reg = ginsn_dw2_regnum (addr, true);
+      /* For all skipped memory operations, check if an update to REG_SP or
+	 REG_FP is involved.  */
+      if ((addr_reg == REG_SP || addr_reg == REG_FP)
+	  && (addr->addr.postind || addr->addr.preind) && addr->addr.writeback)
+	err = AARCH64_GINSN_UNHANDLED_STACKOP;
+    }
+  /* Finally, also check if the missed instructions are affecting REG_SP or
+     REG_FP.  */
+  else if (dest && (dest->type == AARCH64_OPND_Rd
+		    || dest->type == AARCH64_OPND_Rd_SP))
+    {
+      sp_allowed_p = (dest->type == AARCH64_OPND_Rd_SP) ? true : false;
+      dw2_regnum = ginsn_dw2_regnum (dest, sp_allowed_p);
+
+      if (dw2_regnum == REG_SP || dw2_regnum == REG_FP)
+	err = AARCH64_GINSN_UNHANDLED_DEST_REG;
+    }
+
+  return err;
+}
+
+/* Generate one or more generic GAS instructions, a.k.a, ginsns for the current
+   machine instruction.
+
+   Returns the head of linked list of ginsn(s) added, if success; Returns NULL
+   if failure.
+
+   The input ginsn_gen_mode GMODE determines the set of minimal necessary
+   ginsns necessary for correctness of any passes applicable for that mode.
+   For supporting the GINSN_GEN_SCFI generation mode, following is the list of
+   machine instructions that must be translated into the corresponding ginsns
+   to ensure correctness of SCFI:
+     - All instructions affecting the two registers that could potentially
+       be used as the base register for CFA tracking.  For SCFI, the base
+       register for CFA tracking is limited to REG_SP and REG_FP only.
+     - All change of flow instructions: conditional and unconditional branches,
+       call and return from functions.
+     - All instructions that can potentially be a register save / restore
+       operations.
+     - All instructions that may update the stack pointer: pre-indexed and
+     post-indexed stack operations with writeback.
+
+   The function currently supports GINSN_GEN_SCFI ginsn generation mode only.
+   To support other generation modes will require work on this target-specific
+   process of creation of ginsns:
+     - Some of such places are tagged with TBD_GINSN_GEN_NOT_SCFI to serve as
+       possible starting points.
+     - Also note that ginsn representation may need enhancements.  Specifically,
+       note some TBD_GINSN_INFO_LOSS and TBD_GINSN_REPRESENTATION_LIMIT markers.
+   */
+
+static ginsnS *
+aarch64_ginsn_new (const symbolS *insn_end_sym, enum ginsn_gen_mode gmode)
+{
+  int err = 0;
+  ginsnS *ginsn = NULL;
+  unsigned int dw2_regnum;
+  aarch64_opnd_info *dest = NULL;
+  bool sp_allowed_p = false;
+  aarch64_inst *base = &inst.base;
+  const aarch64_opcode *opcode = base->opcode;
+
+  /* Currently supports generation of selected ginsns, sufficient for
+     the use-case of SCFI only.  To remove this condition will require
+     work on this target-specific process of creation of ginsns.  Some
+     of such places are tagged with TBD_GINSN_GEN_NOT_SCFI to serve as
+     examples.  */
+  if (gmode != GINSN_GEN_SCFI)
+    return ginsn;
+
+  switch (opcode->opcode)
+    {
+    case 0x0b200000: /* addsub_ext.  add (extended register).  */
+    case 0x4b200000: /* addsub_ext.  sub (extended register).  */
+      ginsn = aarch64_ginsn_addsub (insn_end_sym);
+      break;
+    case 0x2c800000: /* ldstpair_indexed.  Store fp register pair.  */
+    case 0x28800000: /* ldstpair_indexed.  Store register pair.  */
+      /* pre-index: stp     x29, x30, [sp, -128]!
+	 post-index: stp     x29, x30, [sp] -128.  */
+    case 0x29000000: /* ldstpair_off.  Store register pair (offset).  */
+      /* stp     x19, x20, [sp, 16].  */
+      ginsn = aarch64_ginsn_ldstp (insn_end_sym, true);
+      break;
+    case 0x2cc00000: /* ldstpair_indexed.  Load fp register pair.  */
+    case 0x28c00000: /* ldstpair_indexed.  Load register pair.  */
+      /* pre-index:  ldp     x29, x30, [sp, -128]!
+	 post-index: ldp     x29, x30, [sp], -128.  */
+    case 0x29400000: /* ldstpair_off.  Load register pair (offset).  */
+      /* ldp     x19, x20, [sp, 16].  */
+      ginsn = aarch64_ginsn_ldstp (insn_end_sym, false);
+      break;
+    case 0x38000400: /* ldst_imm9.  Store register (immediate indexed).  */
+      /* strb    w7, [sp, 255]!  */
+    case 0x3c000400: /* ldst_imm9.  Store FP register (immediate indexed).  */
+      /* str     q29, [sp, 44]!  */
+    case 0xb8000400: /* ldst_imm9.  Store register (immediate indexed).  */
+      /* str     x19, [sp], 32  */
+    case 0x78000400: /* ldst_imm9.  strh.  */
+    case 0xb9000000: /* ldst_pos.  Store register (unsigned immediate).  */
+      /* str     x19, [sp]  */
+      ginsn = aarch64_ginsn_ldstr (insn_end_sym, true);
+      break;
+    case 0x38400400: /* ldst_imm9.  Load register (immediate indexed).  */
+      /* ldrb    w7, [sp, 255]!  */
+    case 0x3c400400: /* ldst_imm9.  Load FP register (immediate indexed).  */
+      /* ldr     q29, [sp, 44]!  */
+    case 0xb8400400: /* ldst_imm9.  Load register (immediate indexed).  */
+      /* ldr     x19, [sp], 32  */
+      /* Following sub-word loads can affect stack-pointer due to indexed
+	 addressing mode.  */
+    case 0x38800400: /* ldst_imm9.  ldrsb.  */
+    case 0x78400400: /* ldst_imm9.  ldrh.  */
+    case 0x78800400: /* ldst_imm9.  ldrsh.  */
+    case 0xb8800400: /* ldst_imm9.  ldrsw.  */
+    case 0xb9400000: /* ldst_pos.  Load register (unsigned immediate).  */
+      /* ldr     x19, [sp]  */
+      ginsn = aarch64_ginsn_ldstr (insn_end_sym, false);
+      break;
+    case 0x51000000:
+      /* sub.  */
+      ginsn = aarch64_ginsn_addsub_imm (insn_end_sym);
+      break;
+    case 0x52800000:
+      ginsn = aarch64_ginsn_mov (insn_end_sym);
+      break;
+    case 0x11000000:
+      if (opcode->mask == 0x7ffffc00)
+	ginsn = aarch64_ginsn_mov (insn_end_sym);
+      else if (opcode->mask == 0x7f000000)
+	ginsn = aarch64_ginsn_addsub_imm (insn_end_sym);
+      break;
+    case 0xd65f0000:
+      ginsn = ginsn_new_return (insn_end_sym, true);
+      ginsn_set_where (ginsn);
+      break;
+    case 0x14000000: /* b.  */
+    case 0xd61f0000: /* br.  */
+    case 0x94000000: /* bl.  */
+    case 0xd63f0000: /* blr.  */
+      ginsn = aarch64_ginsn_jump (insn_end_sym);
+      break;
+    case 0x34000000: /* cbz.  */
+    case 0x35000000: /* cbnz.  */
+      /* Although cbz/cbnz has an additional operand and are functionally
+	 distinct from conditional branches, it is fine to use the same ginsn
+	 type for both from the perspective of SCFI.  */
+    case 0x36000000: /* tbz.  */
+    case 0x37000000: /* tbnz.  */
+    case 0x54000000 ... 0x5400000d:
+      ginsn = aarch64_ginsn_jump_cond (insn_end_sym);
+      break;
+    default:
+      /* TBD_GINSN_GEN_NOT_SCFI: Skip all other opcodes uninteresting for
+	 GINSN_GEN_SCFI mode.  */
+      break;
+    }
+
+  if (!ginsn && !aarch64_ginsn_safe_to_skip_p ())
+    {
+      /* For all unhandled insns, check that they no not impact SCFI
+	 correctness.  */
+      err = aarch64_ginsn_unhandled ();
+      switch (err)
+	{
+	case AARCH64_GINSN_UNHANDLED_NONE:
+	  break;
+	case AARCH64_GINSN_UNHANDLED_DEST_REG:
+	  /* Not all writes to REG_FP are harmful in context of SCFI.  Simply
+	     generate a GINSN_TYPE_OTHER with destination set to the
+	     appropriate register.  The SCFI machinery will bail out if this
+	     ginsn affects SCFI correctness.  */
+	  dest = &base->operands[0];
+	  sp_allowed_p = (dest->type == AARCH64_OPND_Rd_SP) ? true : false;
+	  dw2_regnum = ginsn_dw2_regnum (dest, sp_allowed_p);
+	  ginsn = ginsn_new_other (insn_end_sym, true,
+				   GINSN_SRC_IMM, 0,
+				   GINSN_SRC_IMM, 0,
+				   GINSN_DST_REG, dw2_regnum);
+	  ginsn_set_where (ginsn);
+	  break;
+	case AARCH64_GINSN_UNHANDLED_CFG:
+	case AARCH64_GINSN_UNHANDLED_STACKOP:
+	  as_bad (_("SCFI: unhandled op %#x may cause incorrect CFI"),
+		  opcode->opcode);
+	  break;
+	case AARCH64_GINSN_UNHANDLED_UNEXPECTED:
+	  as_bad (_("SCFI: unexpected op %#x may cause incorrect CFI"),
+		  opcode->opcode);
+	  break;
+	default:
+	  abort ();
+	  break;
+	}
+    }
+
+  return ginsn;
+}
+
+#endif /* OBJ_ELF */
+
 static void
 output_inst (struct aarch64_inst *new_inst)
 {
@@ -8520,6 +9240,16 @@ md_assemble (char *str)
 	      output_inst (copy);
 	    }

+#ifdef OBJ_ELF
+	  if (flag_synth_cfi)
+	    {
+	      ginsnS *ginsn;
+	      ginsn = aarch64_ginsn_new (symbol_temp_new_now (),
+					 frch_ginsn_gen_mode ());
+	      frch_ginsn_data_append (ginsn);
+	    }
+#endif
+
 	  /* Issue non-fatal messages if any.  */
 	  output_operand_error_report (str, true);
 	  return;
--- a/gas/config/tc-aarch64.h
+++ b/gas/config/tc-aarch64.h
@@ -263,6 +263,26 @@ extern void aarch64_after_parse_args (void);

 #ifdef OBJ_ELF

+#define TARGET_USE_GINSN 1
+/* Allow GAS to synthesize DWARF CFI for hand-written asm.
+   PS: TARGET_USE_CFIPOP is a pre-condition.  */
+#define TARGET_USE_SCFI 1
+/* Identify the maximum DWARF register number of all the registers being
+   tracked for SCFI.  This is the last DWARF register number of the set
+   of SP, FP, and all callee-saved registers.  For Aarch64, this means 31.  */
+# define SCFI_MAX_REG_ID 31
+/* Identify the DWARF register number of the frame-pointer register.  */
+# define REG_FP 29
+/* Identify the DWARF register number of the link register.  */
+# define REG_LR 30
+/* Identify the DWARF register number of the stack-pointer register.  */
+# define REG_SP 31
+
+#define SCFI_INIT_CFA_OFFSET 0
+
+#define SCFI_CALLEE_SAVED_REG_P(dw2reg)  aarch64_scfi_callee_saved_p (dw2reg)
+extern bool aarch64_scfi_callee_saved_p (uint32_t dw2reg_num);
+
 /* Whether SFrame stack trace info is supported.  */
 extern bool aarch64_support_sframe_p (void);
 #define support_sframe_p aarch64_support_sframe_p
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -5387,9 +5387,8 @@ x86_scfi_callee_saved_p (unsigned int dw2reg_num)
  return false;
 }

-/* Check whether an instruction prefix which affects operation size
-   accompanies.  For insns in the legacy space, setting REX.W takes precedence
-   over the operand-size prefix (66H) when both are used.
+/* Check whether the instruction affecting stack implicitly has a 16-bit
+   operation size.

   The current users of this API are in the handlers for PUSH, POP or other
   instructions which affect the stack pointer implicitly:  the operation size
@@ -5397,9 +5396,20 @@ x86_scfi_callee_saved_p (unsigned int dw2reg_num)
   incremented / decremented (2, 4 or 8).  */

 static bool
-ginsn_opsize_prefix_p (void)
+ginsn_implicitstackop_opsize16_p (void)
 {
-  return (!(i.prefix[REX_PREFIX] & REX_W) && i.prefix[DATA_PREFIX]);
+  bool opsize_prefix_p = false;
+
+  if (i.tm.opcode_modifier.operandconstraint != IMPLICIT_STACK_OP)
+    return opsize_prefix_p;
+
+  /* For insns in the legacy space, setting REX.W takes precedence
+     over the operand-size prefix (66H) when both are used.  */
+  opsize_prefix_p |= !(i.prefix[REX_PREFIX] & REX_W) && i.prefix[DATA_PREFIX];
+  opsize_prefix_p |= (i.tm.opcode_space == SPACE_EVEXMAP4
+		      && i.tm.opcode_modifier.opcodeprefix == PREFIX_0X66);
+
+  return opsize_prefix_p;
 }

 /* Get the DWARF register number for the given register entry.
@@ -5542,7 +5552,7 @@ x86_ginsn_addsub_mem_reg (const symbolS *insn_end_sym)
    }
  else if (i.mem_operands)
    {
-      mem_reg = (i.base_reg) ? i.base_reg : i.index_reg;
+      mem_reg = i.base_reg ? i.base_reg : i.index_reg;
      src1_dw2_regnum = ginsn_dw2_regnum (mem_reg);
      if (i.disp_operands == 1)
 	gdisp = i.op[0].disps->X_add_number;
@@ -5671,7 +5681,7 @@ x86_ginsn_move (const symbolS *insn_end_sym)
      /* mov  disp(%reg), %reg.  */
      if (i.mem_operands)
 	{
-	  src = (i.base_reg) ? i.base_reg : i.index_reg;
+	  src = i.base_reg ? i.base_reg : i.index_reg;
 	  if (i.disp_operands == 1)
 	    src_disp = i.op[0].disps->X_add_number;
 	  src_type = GINSN_SRC_INDIRECT;
@@ -5687,7 +5697,7 @@ x86_ginsn_move (const symbolS *insn_end_sym)
      src = i.op[0].regs;
      if (i.mem_operands)
 	{
-	  dst = (i.base_reg) ? i.base_reg : i.index_reg;
+	  dst = i.base_reg ? i.base_reg : i.index_reg;
 	  if (i.disp_operands == 1)
 	    dst_disp = i.op[1].disps->X_add_number;
 	  dst_type = GINSN_DST_INDIRECT;
@@ -5815,6 +5825,54 @@ x86_ginsn_jump (const symbolS *insn_end_sym, bool cond_p)
  return ginsn;
 }

+static ginsnS *
+x86_ginsn_indirect_jump_call (const symbolS *insn_end_sym)
+{
+  ginsnS *ginsn = NULL;
+  const reg_entry *mem_reg;
+  unsigned int dw2_regnum;
+
+  ginsnS * (*ginsn_func) (const symbolS *sym, bool real_p,
+			  enum ginsn_src_type src_type, unsigned int src_reg,
+			  const symbolS *src_ginsn_sym);
+
+  if (i.tm.extension_opcode == 4)
+    /* 0xFF /4 (jmp r/m).  */
+    ginsn_func = ginsn_new_jump;
+  else if (i.tm.extension_opcode == 2)
+    /* 0xFF /2 (call).  */
+    ginsn_func = ginsn_new_call;
+  else
+    /* Other cases are not expected.  Caller must screen.  */
+    return ginsn;
+
+  if (i.reg_operands)
+    {
+      dw2_regnum = ginsn_dw2_regnum (i.op[0].regs);
+      ginsn = ginsn_func (insn_end_sym, true,
+			  GINSN_SRC_REG, dw2_regnum, NULL);
+      ginsn_set_where (ginsn);
+    }
+  else if (i.mem_operands)
+    {
+      mem_reg = i.base_reg ? i.base_reg : i.index_reg;
+      /* Use dummy register if no base or index.  Unlike other opcodes,
+	 where we simply return NULL, we must try to generate a ginsn here.
+	 Otherwise, the user gets the impression of missing functionality:
+	   - a call insn is an IMPLICIT_STACK_OP.
+	   - jmp insns are necessary for accurate control flow.  */
+      dw2_regnum = (mem_reg
+		    ? ginsn_dw2_regnum (mem_reg)
+		    : GINSN_DW2_REGNUM_RSI_DUMMY);
+      /* jmp/call *sym(,%rN,imm)  or  jmp/call *sym(%rN).  */
+      ginsn = ginsn_func (insn_end_sym, true,
+			  GINSN_SRC_REG, dw2_regnum, NULL);
+      ginsn_set_where (ginsn);
+    }
+
+  return ginsn;
+}
+
 static ginsnS *
 x86_ginsn_enter (const symbolS *insn_end_sym)
 {
@@ -5835,7 +5893,7 @@ x86_ginsn_enter (const symbolS *insn_end_sym)
    }

  /* Check if this is a 16-bit op.  */
-  if (ginsn_opsize_prefix_p ())
+  if (ginsn_implicitstackop_opsize16_p ())
    stack_opnd_size = 2;

  /* If the nesting level is 0, the processor pushes the frame pointer from
@@ -5872,7 +5930,7 @@ x86_ginsn_leave (const symbolS *insn_end_sym)
  int stack_opnd_size = 8;

  /* Check if this is a 16-bit op.  */
-  if (ginsn_opsize_prefix_p ())
+  if (ginsn_implicitstackop_opsize16_p ())
    stack_opnd_size = 2;

  /* The 'leave' instruction copies the contents of the RBP register
@@ -6049,16 +6107,6 @@ x86_ginsn_new (const symbolS *insn_end_sym, enum ginsn_gen_mode gmode)

  opcode = i.tm.base_opcode;

-  /* Until it is clear how to handle APX NDD and other new opcodes, disallow
-     them from SCFI.  */
-  if (is_apx_rex2_encoding ()
-      || (i.tm.opcode_modifier.evex && is_apx_evex_encoding ()))
-    {
-      as_bad (_("SCFI: unsupported APX op %#x may cause incorrect CFI"),
-	      opcode);
-      return ginsn;
-    }
-
  switch (opcode)
    {

@@ -6088,7 +6136,7 @@ x86_ginsn_new (const symbolS *insn_end_sym, enum ginsn_gen_mode gmode)
 	break;
      dw2_regnum = ginsn_dw2_regnum (i.op[0].regs);
      /* Check if operation size is 16-bit.  */
-      if (ginsn_opsize_prefix_p ())
+      if (ginsn_implicitstackop_opsize16_p ())
 	stack_opnd_size = 2;
      ginsn = ginsn_new_sub (insn_end_sym, false,
 			     GINSN_SRC_REG, REG_SP, 0,
@@ -6109,7 +6157,7 @@ x86_ginsn_new (const symbolS *insn_end_sym, enum ginsn_gen_mode gmode)
 	break;
      dw2_regnum = ginsn_dw2_regnum (i.op[0].regs);
      /* Check if operation size is 16-bit.  */
-      if (ginsn_opsize_prefix_p ())
+      if (ginsn_implicitstackop_opsize16_p ())
 	stack_opnd_size = 2;
      ginsn = ginsn_new_load (insn_end_sym, false,
 			      GINSN_SRC_INDIRECT, REG_SP, 0,
@@ -6129,7 +6177,7 @@ x86_ginsn_new (const symbolS *insn_end_sym, enum ginsn_gen_mode gmode)
      /* push reg.  */
      dw2_regnum = ginsn_dw2_regnum (i.op[0].regs);
      /* Check if operation size is 16-bit.  */
-      if (ginsn_opsize_prefix_p ())
+      if (ginsn_implicitstackop_opsize16_p ())
 	stack_opnd_size = 2;
      ginsn = ginsn_new_sub (insn_end_sym, false,
 			     GINSN_SRC_REG, REG_SP, 0,
@@ -6153,7 +6201,7 @@ x86_ginsn_new (const symbolS *insn_end_sym, enum ginsn_gen_mode gmode)
 			      GINSN_DST_REG, dw2_regnum);
      ginsn_set_where (ginsn);
      /* Check if operation size is 16-bit.  */
-      if (ginsn_opsize_prefix_p ())
+      if (ginsn_implicitstackop_opsize16_p ())
 	stack_opnd_size = 2;
      ginsn_next = ginsn_new_add (insn_end_sym, false,
 				  GINSN_SRC_REG, REG_SP, 0,
@@ -6168,7 +6216,7 @@ x86_ginsn_new (const symbolS *insn_end_sym, enum ginsn_gen_mode gmode)
      if (i.tm.opcode_space != SPACE_BASE)
 	break;
      /* Check if operation size is 16-bit.  */
-      if (ginsn_opsize_prefix_p ())
+      if (ginsn_implicitstackop_opsize16_p ())
 	stack_opnd_size = 2;
      /* Skip getting the value of imm from machine instruction
 	 because this is not important for SCFI.  */
@@ -6184,7 +6232,7 @@ x86_ginsn_new (const symbolS *insn_end_sym, enum ginsn_gen_mode gmode)
      gas_assert (!ginsn_link_next (ginsn, ginsn_next));
      break;

-    /* PS: Opcodes 0x80 ... 0x8f with opcode_space SPACE_0F are present
+    /* PS: JCC Opcodes 0x80 ... 0x8f (opcode_space SPACE_0F) are present
       only after relaxation.  They do not need to be handled for ginsn
       creation.  */
    case 0x70 ... 0x7f:
@@ -6223,7 +6271,7 @@ x86_ginsn_new (const symbolS *insn_end_sym, enum ginsn_gen_mode gmode)
      /* pop to reg/mem.  */
      if (i.mem_operands)
 	{
-	  mem_reg = (i.base_reg) ? i.base_reg : i.index_reg;
+	  mem_reg = i.base_reg ? i.base_reg : i.index_reg;
 	  /* Use dummy register if no base or index.  Unlike other opcodes,
 	     ginsns must be generated as this affect stack pointer.  */
 	  dw2_regnum = (mem_reg
@@ -6237,7 +6285,7 @@ x86_ginsn_new (const symbolS *insn_end_sym, enum ginsn_gen_mode gmode)
 			      GINSN_DST_INDIRECT, dw2_regnum);
      ginsn_set_where (ginsn);
      /* Check if operation size is 16-bit.  */
-      if (ginsn_opsize_prefix_p ())
+      if (ginsn_implicitstackop_opsize16_p ())
 	stack_opnd_size = 2;
      ginsn_next = ginsn_new_add (insn_end_sym, false,
 				  GINSN_SRC_REG, REG_SP, 0,
@@ -6252,7 +6300,7 @@ x86_ginsn_new (const symbolS *insn_end_sym, enum ginsn_gen_mode gmode)
 	break;
      /* pushf / pushfq.  */
      /* Check if operation size is 16-bit.  */
-      if (ginsn_opsize_prefix_p ())
+      if (ginsn_implicitstackop_opsize16_p ())
 	stack_opnd_size = 2;
      ginsn = ginsn_new_sub (insn_end_sym, false,
 			     GINSN_SRC_REG, REG_SP, 0,
@@ -6275,7 +6323,7 @@ x86_ginsn_new (const symbolS *insn_end_sym, enum ginsn_gen_mode gmode)
 	break;
      /* popf / popfq.  */
      /* Check if operation size is 16-bit.  */
-      if (ginsn_opsize_prefix_p ())
+      if (ginsn_implicitstackop_opsize16_p ())
 	stack_opnd_size = 2;
      /* FIXME - hardcode the actual DWARF reg number value.  As for SCFI
 	 correctness, although this behaves simply a placeholder value; its
@@ -6300,7 +6348,7 @@ x86_ginsn_new (const symbolS *insn_end_sym, enum ginsn_gen_mode gmode)
      if (i.tm.extension_opcode == 6)
 	{
 	  /* Check if operation size is 16-bit.  */
-	  if (ginsn_opsize_prefix_p ())
+	  if (ginsn_implicitstackop_opsize16_p ())
 	    stack_opnd_size = 2;
 	  ginsn = ginsn_new_sub (insn_end_sym, false,
 				 GINSN_SRC_REG, REG_SP, 0,
@@ -6309,7 +6357,7 @@ x86_ginsn_new (const symbolS *insn_end_sym, enum ginsn_gen_mode gmode)
 	  ginsn_set_where (ginsn);
 	  if (i.mem_operands)
 	    {
-	      mem_reg = (i.base_reg) ? i.base_reg : i.index_reg;
+	      mem_reg = i.base_reg ? i.base_reg : i.index_reg;
 	      /* Use dummy register if no base or index.  Unlike other opcodes,
 		 ginsns must be generated as this affect stack pointer.  */
 	      dw2_regnum = (mem_reg
@@ -6324,50 +6372,9 @@ x86_ginsn_new (const symbolS *insn_end_sym, enum ginsn_gen_mode gmode)
 	  ginsn_set_where (ginsn_next);
 	  gas_assert (!ginsn_link_next (ginsn, ginsn_next));
 	}
-      else if (i.tm.extension_opcode == 4)
-	{
-	  /* jmp r/m.  E.g., notrack jmp *%rax.  */
-	  if (i.reg_operands)
-	    {
-	      dw2_regnum = ginsn_dw2_regnum (i.op[0].regs);
-	      ginsn = ginsn_new_jump (insn_end_sym, true,
-				      GINSN_SRC_REG, dw2_regnum, NULL);
-	      ginsn_set_where (ginsn);
-	    }
-	  else if (i.mem_operands && i.index_reg)
-	    {
-	      /* jmp    *0x0(,%rax,8).  */
-	      dw2_regnum = ginsn_dw2_regnum (i.index_reg);
-	      ginsn = ginsn_new_jump (insn_end_sym, true,
-				      GINSN_SRC_REG, dw2_regnum, NULL);
-	      ginsn_set_where (ginsn);
-	    }
-	  else if (i.mem_operands && i.base_reg)
-	    {
-	      dw2_regnum = ginsn_dw2_regnum (i.base_reg);
-	      ginsn = ginsn_new_jump (insn_end_sym, true,
-				      GINSN_SRC_REG, dw2_regnum, NULL);
-	      ginsn_set_where (ginsn);
-	    }
-	}
-      else if (i.tm.extension_opcode == 2)
-	{
-	  /* 0xFF /2 (call).  */
-	  if (i.reg_operands)
-	    {
-	      dw2_regnum = ginsn_dw2_regnum (i.op[0].regs);
-	      ginsn = ginsn_new_call (insn_end_sym, true,
-				      GINSN_SRC_REG, dw2_regnum, NULL);
-	      ginsn_set_where (ginsn);
-	    }
-	  else if (i.mem_operands && i.base_reg)
-	    {
-	      dw2_regnum = ginsn_dw2_regnum (i.base_reg);
-	      ginsn = ginsn_new_call (insn_end_sym, true,
-				      GINSN_SRC_REG, dw2_regnum, NULL);
-	      ginsn_set_where (ginsn);
-	    }
-	}
+      else if (i.tm.extension_opcode == 4 || i.tm.extension_opcode == 2)
+	ginsn = x86_ginsn_indirect_jump_call (insn_end_sym);
+
      break;

    case 0xc2: /* ret imm16.  */
--- a/gas/doc/scfi/scfi-paper.tex
+++ b/gas/doc/scfi/scfi-paper.tex
--- a/gas/ginsn.c
+++ b/gas/ginsn.c
@@ -614,6 +614,8 @@ gbb_cleanup (gbbS **bbp)
  *bbp = NULL;
 }

+/* Add an edge from the source bb FROM_BB to the sink bb TO_BB.  */
+
 static void
 bb_add_edge (gbbS* from_bb, gbbS *to_bb)
 {
@@ -638,7 +640,7 @@ bb_add_edge (gbbS* from_bb, gbbS *to_bb)
    }
  else
    {
-      /* Get the tail of the list.  */
+      /* Get the head of the list.  */
      tmpedge = from_bb->out_gedges;
      while (tmpedge)
 	{
@@ -689,6 +691,9 @@ static gbbS *
 add_bb_at_ginsn (const symbolS *func, gcfgS *gcfg, ginsnS *ginsn, gbbS *prev_bb,
 		 int *errp);

+/* Return the already existing basic block (if present), which begins with
+   GINSN, in the given GCFG.  Return NULL otherwise.  */
+
 static gbbS *
 find_bb (gcfgS *gcfg, ginsnS *ginsn)
 {
@@ -708,13 +713,18 @@ find_bb (gcfgS *gcfg, ginsnS *ginsn)
 	      break;
 	    }
 	}
-      /* Must be found if ginsn is visited.  */
+      /* Must be found because ginsn is visited.  */
      gas_assert (found_bb);
    }

  return found_bb;
 }

+/* Get the basic block starting at GINSN in the GCFG.
+
+   If not already present, the function will make one, while adding an edge
+   from the PREV_BB to it.  */
+
 static gbbS *
 find_or_make_bb (const symbolS *func, gcfgS *gcfg, ginsnS *ginsn, gbbS *prev_bb,
 		 int *errp)
@@ -722,26 +732,40 @@ find_or_make_bb (const symbolS *func, gcfgS *gcfg, ginsnS *ginsn, gbbS *prev_bb,
  gbbS *found_bb = NULL;

  found_bb = find_bb (gcfg, ginsn);
-  if (found_bb)
-    return found_bb;
+  if (!found_bb)
+    found_bb = add_bb_at_ginsn (func, gcfg, ginsn, prev_bb, errp);

-  return add_bb_at_ginsn (func, gcfg, ginsn, prev_bb, errp);
+  gas_assert (found_bb);
+  gas_assert (found_bb->first_ginsn == ginsn);
+
+  return found_bb;
 }

-/* Add the basic block starting at GINSN to the given GCFG.
-   Also adds an edge from the PREV_BB to the newly added basic block.
+/* Add basic block(s) for all reachable, unvisited ginsns, starting from GINSN,
+   to the given GCFG.  Also add an edge from the PREV_BB to the root of the
+   newly added basic block(s).

-   This is a recursive function which returns the root of the added
-   basic blocks.  */
+   This is a recursive function which returns the root of the added basic
+   blocks.  */

 static gbbS *
 add_bb_at_ginsn (const symbolS *func, gcfgS *gcfg, ginsnS *ginsn, gbbS *prev_bb,
 		 int *errp)
 {
+  gbbS *root_bb = NULL;
  gbbS *current_bb = NULL;
  ginsnS *target_ginsn = NULL;
  const symbolS *taken_label;

+  /* Create a new bb.  N.B. The caller must ensure bb with this ginsn does not
+     already exist.  */
+  gas_assert (!find_bb (gcfg, ginsn));
+  root_bb = XCNEW (gbbS);
+  cfg_add_bb (gcfg, root_bb);
+  root_bb->first_ginsn = ginsn;
+
+  current_bb = root_bb;
+
  while (ginsn)
    {
      /* Skip these as they may be right after a GINSN_TYPE_RETURN.
@@ -749,6 +773,8 @@ add_bb_at_ginsn (const symbolS *func, gcfgS *gcfg, ginsnS *ginsn, gbbS *prev_bb,
 	 end of bb, and a logical exit from function.  */
      if (GINSN_F_FUNC_END_P (ginsn))
 	{
+	  /* Dont mark them visited yet though, leaving the option of these
+	     being visited via other control flows as applicable.  */
 	  ginsn = ginsn->next;
 	  continue;
 	}
@@ -765,27 +791,27 @@ add_bb_at_ginsn (const symbolS *func, gcfgS *gcfg, ginsnS *ginsn, gbbS *prev_bb,
 	    bb_add_edge (prev_bb, current_bb);
 	  break;
 	}
-      else if (current_bb && GINSN_F_USER_LABEL_P (ginsn))
+      else if (current_bb && current_bb->first_ginsn != ginsn
+	       && GINSN_F_USER_LABEL_P (ginsn))
 	{
-	  /* Create new bb starting at this label ginsn.  */
+	  /* Create new bb starting at ginsn for (user-defined) label.  This is
+	     likely going to be a destination of a some control flow.  */
 	  prev_bb = current_bb;
-	  find_or_make_bb (func, gcfg, ginsn, prev_bb, errp);
+	  current_bb = find_or_make_bb (func, gcfg, ginsn, prev_bb, errp);
+	  bb_add_edge (prev_bb, current_bb);
 	  break;
 	}

      if (current_bb == NULL)
 	{
-	  /* Create a new bb.  */
 	  current_bb = XCNEW (gbbS);
 	  cfg_add_bb (gcfg, current_bb);
+	  current_bb->first_ginsn = ginsn;
 	  /* Add edge for the Not Taken, or Fall-through path.  */
 	  if (prev_bb)
 	    bb_add_edge (prev_bb, current_bb);
 	}

-      if (current_bb->first_ginsn == NULL)
-	current_bb->first_ginsn = ginsn;
-
      ginsn->visited = true;
      current_bb->num_ginsns++;
      current_bb->last_ginsn = ginsn;
@@ -809,16 +835,21 @@ add_bb_at_ginsn (const symbolS *func, gcfgS *gcfg, ginsnS *ginsn, gbbS *prev_bb,
 	      taken_label = ginsn->src[0].sym;
 	      gas_assert (taken_label);

-	      /* Preserve the prev_bb to be the dominator bb as we are
-		 going to follow the taken path of the conditional branch
-		 soon.  */
+	      /* Preserve the prev_bb to be the source bb as we are going to
+		 follow the taken path of the conditional branch soon.  */
 	      prev_bb = current_bb;

 	      /* Follow the target on the taken path.  */
 	      target_ginsn = label_ginsn_map_find (taken_label);
 	      /* Add the bb for the target of the taken branch.  */
 	      if (target_ginsn)
-		find_or_make_bb (func, gcfg, target_ginsn, prev_bb, errp);
+		{
+		  current_bb = find_or_make_bb (func, gcfg, target_ginsn,
+						prev_bb, errp);
+		  gas_assert (prev_bb);
+		  bb_add_edge (prev_bb, current_bb);
+		  current_bb = NULL;
+		}
 	      else
 		{
 		  *errp = GCFG_JLABEL_NOT_PRESENT;
@@ -826,27 +857,39 @@ add_bb_at_ginsn (const symbolS *func, gcfgS *gcfg, ginsnS *ginsn, gbbS *prev_bb,
 				 _("missing label '%s' in func '%s' may result in imprecise cfg"),
 				 S_GET_NAME (taken_label), S_GET_NAME (func));
 		}
+
+	      if (ginsn->type == GINSN_TYPE_JUMP_COND)
+		{
 		  /* Add the bb for the fall through path.  */
-	      find_or_make_bb (func, gcfg, ginsn->next, prev_bb, errp);
+		  current_bb = find_or_make_bb (func, gcfg, ginsn->next,
+						prev_bb, errp);
+		  gas_assert (prev_bb);
+		  bb_add_edge (prev_bb, current_bb);
+		  current_bb = NULL;
+		}
+	      else
+		/* Unconditional jump.  Current BB has been processed.  */
+		current_bb = NULL;
 	    }
 	 else
 	   {
 	     gas_assert (ginsn->type == GINSN_TYPE_RETURN
 			 || (ginsn->type == GINSN_TYPE_JUMP
 			     && !ginsn_direct_local_jump_p (ginsn)));
+	     /* Current BB has been processed.  */
+	     current_bb = NULL;
+
 	     /* We'll come back to the ginsns following GINSN_TYPE_RETURN or
 		other (non-local) unconditional jmps from another path if they
 		are indeed reachable code.  */
 	     break;
 	   }
-
-	 /* Current BB has been processed.  */
-	 current_bb = NULL;
 	}
+
      ginsn = ginsn->next;
    }

-  return current_bb;
+  return root_bb;
 }

 static int
--- a/gas/scfi.c
+++ b/gas/scfi.c
@@ -155,7 +155,7 @@ cmp_scfi_state (scfi_stateS *state1, scfi_stateS *state2)
  int ret;

  if (!state1 || !state2)
-    ret = 1;
+    return 1;

  /* Skip comparing the scratch[] value of registers.  The user visible
     unwind information is derived from the regs[] from the SCFI state.  */
@@ -164,10 +164,12 @@ cmp_scfi_state (scfi_stateS *state1, scfi_stateS *state2)

  /* For user functions which perform dynamic stack allocation, after switching
     t REG_FP based CFA tracking, it is perfectly possible to have stack usage
-     in some control flows.  However, double-checking that all control flows
-     have the same idea of CFA tracking before this wont hurt.  */
-  gas_assert (state1->regs[REG_CFA].base == state2->regs[REG_CFA].base);
-  if (state1->regs[REG_CFA].base == REG_SP)
+     in some control flows.  Further, the different control flows may even not
+     have the same idea of CFA tracking (likely later necessitating generation
+     of .cfi_remember_state / .cfi_restore_state pair).  */
+  ret |= state1->regs[REG_CFA].base != state2->regs[REG_CFA].base;
+
+  if (!ret && state1->regs[REG_CFA].base == REG_SP)
    ret |= state1->stack_size != state2->stack_size;

  ret |= state1->traceable_p != state2->traceable_p;
@@ -911,11 +913,11 @@ gen_scfi_ops (ginsnS *ginsn, scfi_stateS *state)
  return ret;
 }

-/* Recursively perform forward flow of the (unwind information) SCFI state
+/* Recursively perform forward flow of the (unwind information) SCFI STATE
   starting at basic block GBB.

-   The forward flow process propagates the SCFI state at exit of a basic block
-   to the successor basic block.
+   The core of forward flow process takes the SCFI state at the entry of a bb
+   and updates it incrementally as per the semantics of each ginsn in the bb.

   Returns error code, if any.  */

@@ -961,6 +963,8 @@ forward_flow_scfi_state (gcfgS *gcfg, gbbS *gbb, scfi_stateS *state)
      bb_for_each_edge(gbb, gedge)
 	{
 	  gbb = gedge->dst_bb;
+	  /* Ensure that the state is the one from the exit of the prev bb.  */
+	  memcpy (state, prev_bb->exit_state, sizeof (scfi_stateS));
 	  if (gbb->visited)
 	    {
 	      ret = cmp_scfi_state (gbb->entry_state, state);
--- a/gas/testsuite/gas/scfi/README
+++ b/gas/testsuite/gas/scfi/README
@@ -1,6 +1,6 @@
 Notes on the SCFI testsuite in GAS:

-* At this time, SCFI machinery is only supported for x86_64.
+* At this time, SCFI machinery is only supported for x86_64 and aarch64.

 * When adding more tests, please keep CFI annotations updated in the .s files.
  Ideally the test should be run with and without --scfi (as is done currently
--- a/gas/testsuite/gas/scfi/aarch64/ginsn-cofi-1.l
+++ b/gas/testsuite/gas/scfi/aarch64/ginsn-cofi-1.l
@@ -0,0 +1,30 @@
+.*: Assembler messages:
+.*:16: Error: untraceable control flow for func 'foo'
+
+AARCH64 GAS  .*
+
+   1              	# Testcase for a variety of change of flow instructions
+   2              	# Because some of these are indirect branches, SCFI will bail out
+   3              	# with an error.  This test merely checks that the ginsn creation
+   4              	# process can handle these insns gracefully.
+   5              		.text
+   6              		.align  2
+   7              		.global foo
+   8              		.type   foo, %function
+   8              	ginsn: SYM FUNC_BEGIN
+   9              	foo:
+   9              	ginsn: SYM foo
+  10 \?\?\?\? 00000094 		bl      dump_bt
+  10              	ginsn: CALL
+  11 \?\?\?\? 02000014 		b       .L3
+  11              	ginsn: JMP 
+  12 \?\?\?\? 20021FD6 		br      x17
+  12              	ginsn: JMP %r17, 
+  13              	.L3:
+  13              	ginsn: SYM .L3
+  14 \?\?\?\? 60003FD6 		blr     x3
+  14              	ginsn: CALL
+  15 \?\?\?\? C0035FD6 		ret
+  15              	ginsn: RET
+  16              		.size   foo, .-foo
+  16              	ginsn: SYM FUNC_END
--- a/gas/testsuite/gas/scfi/aarch64/ginsn-cofi-1.s
+++ b/gas/testsuite/gas/scfi/aarch64/ginsn-cofi-1.s
@@ -0,0 +1,16 @@
+# Testcase for a variety of change of flow instructions
+# Because some of these are indirect branches, SCFI will bail out
+# with an error.  This test merely checks that the ginsn creation
+# process can handle these insns gracefully.
+	.text
+	.align  2
+	.global foo
+	.type   foo, %function
+foo:
+	bl      dump_bt
+	b       .L3
+	br      x17
+.L3:
+	blr     x3
+	ret
+	.size   foo, .-foo
--- a/gas/testsuite/gas/scfi/aarch64/ginsn-ldst-1.l
+++ b/gas/testsuite/gas/scfi/aarch64/ginsn-ldst-1.l
@@ -0,0 +1,40 @@
+AARCH64 GAS  .*
+
+   1              	# Testcase for a variety of ld st instructions
+   2              		.text
+   3              		.align  2
+   4              		.global foo
+   5              		.type   foo, %function
+   5              	ginsn: SYM FUNC_BEGIN
+   6              	foo:
+   6              	ginsn: SYM foo
+   7              	# ldstpair_indexed
+   8 0000 FFFF8629 		stp     wzr, wzr, \[sp, 52\]!
+   8              	ginsn: ADD %r31, 52, %r31
+   8              	ginsn: STORE %r1, \[%r31\+0\]
+   8              	ginsn: STORE %r1, \[%r31\+4\]
+   9 0004 E00782A9 		stp     x0, x1, \[sp, 32\]!
+   9              	ginsn: ADD %r31, 32, %r31
+   9              	ginsn: STORE %r0, \[%r31\+0\]
+   9              	ginsn: STORE %r1, \[%r31\+8\]
+  10 0008 E827BC6D 		stp     d8, d9, \[sp, -64\]!
+  10              	ginsn: ADD %r31, -64, %r31
+  11              	# Following is skipped from ginsn generation
+  12 000c E00702AD 		stp     q0, q1, \[sp, 64\]
+  13              	# ldstpair_off
+  14 0010 FFFF0629 		stp     wzr, wzr, \[sp, 52\]
+  14              	ginsn: STORE %r1, \[%r31\+52\]
+  14              	ginsn: STORE %r1, \[%r31\+56\]
+  15 0014 1F7840AD 		ldp     q31, q30, \[x0\]
+  16 0018 E827C46C 		ldp     d8,  d9,  \[sp\], 64
+  16              	ginsn: ADD %r31, 64, %r31
+  17              	# ldst_imm9
+  18 001c E7FF4F38 		ldrb    w7, \[sp, 255\]!
+  18              	ginsn: ADD %r31, 255, %r31
+  18              	ginsn: LOAD \[%r31\+0\], %r7
+  19 0020 FDCFC23C 		ldr     q29, \[sp, 44\]!
+  19              	ginsn: ADD %r31, 44, %r31
+  20 0024 C0035FD6 		ret
+  20              	ginsn: RET
+  21              		.size   foo, .-foo
+  21              	ginsn: SYM FUNC_END
--- a/gas/testsuite/gas/scfi/aarch64/ginsn-ldst-1.s
+++ b/gas/testsuite/gas/scfi/aarch64/ginsn-ldst-1.s
@@ -0,0 +1,21 @@
+# Testcase for a variety of ld st instructions
+	.text
+	.align  2
+	.global foo
+	.type   foo, %function
+foo:
+# ldstpair_indexed
+	stp     wzr, wzr, [sp, 52]!
+	stp     x0, x1, [sp, 32]!
+	stp     d8, d9, [sp, -64]!
+# Following is skipped from ginsn generation
+	stp     q0, q1, [sp, 64]
+# ldstpair_off
+	stp     wzr, wzr, [sp, 52]
+	ldp     q31, q30, [x0]
+	ldp     d8,  d9,  [sp], 64
+# ldst_imm9
+	ldrb    w7, [sp, 255]!
+	ldr     q29, [sp, 44]!
+	ret
+	.size   foo, .-foo
--- a/gas/testsuite/gas/scfi/aarch64/ginsn-misc-1.l
+++ b/gas/testsuite/gas/scfi/aarch64/ginsn-misc-1.l
@@ -0,0 +1,32 @@
+.*: Assembler messages:
+.*:9: Error: SCFI: unsupported stack manipulation pattern
+.*:15: Error: SCFI: forward pass failed for func 'foo'
+
+AARCH64 GAS  .*
+
+
+   1              	# Testcase for a variety of misc instructions
+   2              	# Ensure graceful handling, irrespective of ginsn generation
+   3              	symbol:
+   4 \?\?\?\? 7700     	        .string "w"
+   5              	
+   6              		.type   foo, %function
+   6              	ginsn: SYM FUNC_BEGIN
+   7              	foo:
+   7              	ginsn: SYM foo
+   8 \?\?\?\? 00001024 		mov     x16, 4384
+   8      82D2
+   8              	ginsn: MOV 4384, %r16
+   9 \?\?\?\? FF63308B 		add     sp, sp, x16
+   9              	ginsn: ADD %r31, %r16, %r31
+  10 \?\?\?\? 00000090 	        adrp    x0, symbol
+  11 \?\?\?\? 1F000091 		add     sp, x0, :lo12:symbol
+  11              	ginsn: OTH 0, 0, %r31
+  12 \?\?\?\? FF0F00D1 		sub     sp, sp, 3
+  12              	ginsn: SUB %r31, 3, %r31
+  13 \?\?\?\? FF0F0091 		add     sp, sp, 3
+  13              	ginsn: ADD %r31, 3, %r31
+  14 \?\?\?\? C0035FD6 		ret
+  14              	ginsn: RET
+  15              		.size   foo,.-foo
+  15              	ginsn: SYM FUNC_END
--- a/gas/testsuite/gas/scfi/aarch64/ginsn-misc-1.s
+++ b/gas/testsuite/gas/scfi/aarch64/ginsn-misc-1.s
@@ -0,0 +1,15 @@
+# Testcase for a variety of misc instructions
+# Ensure graceful handling, irrespective of ginsn generation
+symbol:
+        .string "w"
+
+	.type   foo, %function
+foo:
+	mov     x16, 4384
+	add     sp, sp, x16
+        adrp    x0, symbol
+	add     sp, x0, :lo12:symbol
+	sub     sp, sp, 3
+	add     sp, sp, 3
+	ret
+	.size   foo,.-foo
--- a/gas/testsuite/gas/scfi/aarch64/scfi-aarch64.exp
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-aarch64.exp
@@ -0,0 +1,59 @@
+# Copyright (C) 2022-2023 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston, MA 02110-1301, USA.
+
+if { ![is_elf_format] } then {
+    return
+}
+
+# common tests
+if  { ([istarget "aarch64-*-*"]) } then {
+
+    global ASFLAGS
+    set old_ASFLAGS "$ASFLAGS"
+
+    run_list_test "ginsn-cofi-1" "--scfi=experimental -ali --warn"
+    run_list_test "ginsn-ldst-1" "--scfi=experimental -ali --warn"
+    run_list_test "ginsn-misc-1" "--scfi=experimental -ali --warn"
+
+    run_list_test "scfi-diag-1" "--scfi=experimental"
+
+    run_list_test "scfi-unsupported-1" "--scfi=experimental"
+
+    run_dump_test "scfi-ldrp-1"
+    run_list_test "scfi-ldrp-1" "--scfi=experimental --warn"
+    run_dump_test "scfi-ldrp-2"
+    run_list_test "scfi-ldrp-2" "--scfi=experimental --warn"
+
+    run_dump_test "scfi-strp-1"
+    run_list_test "scfi-strp-1" "--scfi=experimental --warn"
+    run_dump_test "scfi-strp-2"
+    run_list_test "scfi-strp-2" "--scfi=experimental --warn"
+
+    run_dump_test "scfi-cb-1"
+    run_list_test "scfi-cb-1" "--scfi=experimental --warn"
+    run_dump_test "scfi-cond-br-1"
+    run_list_test "scfi-cond-br-1" "--scfi=experimental --warn"
+
+    run_dump_test "scfi-cfg-1"
+    run_list_test "scfi-cfg-1" "--scfi=experimental --warn"
+
+    run_dump_test "scfi-cfg-2"
+    run_list_test "scfi-cfg-2" "--scfi=experimental --warn"
+
+    run_dump_test "scfi-cfg-3"
+    run_list_test "scfi-cfg-3" "--scfi=experimental --warn"
+
+}
--- a/gas/testsuite/gas/scfi/aarch64/scfi-cb-1.d
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-cb-1.d
@@ -0,0 +1,20 @@
+#as: --scfi=experimental -W
+#objdump: -Wf
+#name: Synthesize CFI for comp branch 1
+#...
+Contents of the .eh_frame section:
+
+
+0+0000 0+0010 0+0000 CIE
+  Version:               1
+  Augmentation:          "zR"
+  Code alignment factor: 4
+  Data alignment factor: -8
+  Return address column: 30
+  Augmentation data:     1b
+  DW_CFA_def_cfa: r31 \(sp\) ofs 0
+
+0+0014 0+0010 00000018 FDE cie=00000000 pc=0+0000..0+0014
+  DW_CFA_nop
+
+#pass
--- a/gas/testsuite/gas/scfi/aarch64/scfi-cb-1.l
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-cb-1.l
@@ -0,0 +1,2 @@
+.*Assembler messages:
+.*5: Warning: SCFI ignores most user-specified CFI directives
--- a/gas/testsuite/gas/scfi/aarch64/scfi-cb-1.s
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-cb-1.s
@@ -0,0 +1,14 @@
+	.text
+	.global foo
+	.type  foo, %function
+foo:
+	.cfi_startproc
+.L7:
+	add     w4, w3, w1
+	cbnz    w4, .L7
+	cbz     w4, .L10
+	tbnz    w0, #31, .L7
+.L10:
+	ret
+	.cfi_endproc
+	.size   foo, .-foo
--- a/gas/testsuite/gas/scfi/aarch64/scfi-cfg-1.d
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-cfg-1.d
@@ -0,0 +1,31 @@
+#as: --scfi=experimental -W
+#objdump: -Wf
+#name: Synthesize CFI for cfg 1
+#...
+Contents of the .eh_frame section:
+
+
+0+0000 0+0010 0+0000 CIE
+  Version:               1
+  Augmentation:          "zR"
+  Code alignment factor: 4
+  Data alignment factor: -8
+  Return address column: 30
+  Augmentation data:     1b
+  DW_CFA_def_cfa: r31 \(sp\) ofs 0
+
+0+0014 0+0020 0+0018 FDE cie=00000000 pc=0+0000..0+0068
+  DW_CFA_advance_loc: 4 to 0+0004
+  DW_CFA_def_cfa_offset: 48
+  DW_CFA_offset: r29 \(x29\) at cfa-48
+  DW_CFA_offset: r30 \(x30\) at cfa-40
+  DW_CFA_advance_loc: 4 to 0+0008
+  DW_CFA_def_cfa_register: r29 \(x29\)
+  DW_CFA_advance_loc: 92 to 0+0064
+  DW_CFA_def_cfa_register: r31 \(sp\)
+  DW_CFA_restore: r29 \(x29\)
+  DW_CFA_restore: r30 \(x30\)
+  DW_CFA_def_cfa_offset: 0
+  DW_CFA_nop
+
+#pass
--- a/gas/testsuite/gas/scfi/aarch64/scfi-cfg-1.l
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-cfg-1.l
@@ -0,0 +1,2 @@
+.*Assembler messages:
+.*6: Warning: SCFI ignores most user-specified CFI directives
--- a/gas/testsuite/gas/scfi/aarch64/scfi-cfg-1.s
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-cfg-1.s
@@ -0,0 +1,46 @@
+# Testcase for forward flow of SCFI information
+# and CFG creation as well.  This testcase has two backward edges
+# (one of which is a loop) and one exit path.
+	.type   foo, %function
+foo:
+	.cfi_startproc
+	stp    x29, x30, [sp, -48]!
+	.cfi_def_cfa_offset 48
+	.cfi_offset 29, -48
+	.cfi_offset 30, -40
+	mov     x29, sp
+	.cfi_def_cfa_register 29
+	str     x0, [sp, 24]
+	adrp    x0, :got:xyz
+	str     x0, [sp, 40]
+	b       .L7
+.L10:
+	ldr     x0, [sp, 40]
+	ldr     x0, [x0]
+	mov     x1, x0
+	ldr     x0, [sp, 24]
+	bl      strcmp
+	cmp     w0, 0
+	bne     .L8
+	ldr     x0, [sp, 40]
+	ldr     w0, [x0, 8]
+	b       .L9
+.L8:
+	ldr     x0, [sp, 40]
+	add     x0, x0, 24
+	str     x0, [sp, 40]
+.L7:
+	ldr     x0, [sp, 40]
+	ldr     w0, [x0, 8]
+	cmp     w0, 0
+	bne     .L10
+	mov     w0, 0
+.L9:
+	ldp     x29, x30, [sp], 48
+	.cfi_def_cfa_register 31
+	.cfi_restore 30
+	.cfi_restore 29
+	.cfi_def_cfa_offset 0
+	ret
+	.cfi_endproc
+	.size   foo, .-foo
--- a/gas/testsuite/gas/scfi/aarch64/scfi-cfg-2.d
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-cfg-2.d
@@ -0,0 +1,40 @@
+#as: --scfi=experimental -W
+#objdump: -Wf
+#name: Synthesize CFI for cfg 2
+#...
+Contents of the .eh_frame section:
+
+
+0+0000 0+0010 0+0000 CIE
+  Version:               1
+  Augmentation:          "zR"
+  Code alignment factor: 4
+  Data alignment factor: -8
+  Return address column: 30
+  Augmentation data:     1b
+  DW_CFA_def_cfa: r31 \(sp\) ofs 0
+
+0+0014 0+[0-9a-f]+ 0+0018 FDE cie=00000000 pc=0+0000..0+0028
+  DW_CFA_advance_loc: 4 to 0+0004
+  DW_CFA_def_cfa_offset: 48
+  DW_CFA_offset: r29 \(x29\) at cfa-48
+  DW_CFA_offset: r30 \(x30\) at cfa-40
+  DW_CFA_advance_loc: 4 to 0+0008
+  DW_CFA_def_cfa_register: r29 \(x29\)
+  DW_CFA_advance_loc: 8 to 0+0010
+  DW_CFA_remember_state
+  DW_CFA_advance_loc: 8 to 0+0018
+  DW_CFA_def_cfa_register: r31 \(sp\)
+  DW_CFA_restore: r29 \(x29\)
+  DW_CFA_restore: r30 \(x30\)
+  DW_CFA_def_cfa_offset: 0
+  DW_CFA_advance_loc: 4 to 0+001c
+  DW_CFA_restore_state
+  DW_CFA_advance_loc: 8 to 0+0024
+  DW_CFA_def_cfa_register: r31 \(sp\)
+  DW_CFA_restore: r29 \(x29\)
+  DW_CFA_restore: r30 \(x30\)
+  DW_CFA_def_cfa_offset: 0
+  DW_CFA_nop
+
+#pass
--- a/gas/testsuite/gas/scfi/aarch64/scfi-cfg-2.l
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-cfg-2.l
@@ -0,0 +1,2 @@
+.*Assembler messages:
+.*13: Warning: SCFI ignores most user-specified CFI directives
--- a/gas/testsuite/gas/scfi/aarch64/scfi-cfg-2.s
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-cfg-2.s
@@ -0,0 +1,42 @@
+# Testcase for backward flow of SCFI state.
+# The cfg has two exit paths, with epilogue duplicated in
+# the two.
+#
+# SCFI must synthesize the remember_state / restore_state pair.
+# Note how SCFI does not necessary generate the least number of
+# CFI directives (.cfi_remember_state can possibly be clubbed
+# together with other immediately following CFI directives).
+# This is not a correctness issue, however.
+	.global foo
+	.type   foo, %function
+foo:
+	.cfi_startproc
+	stp     x29, x30, [sp, -48]!
+	.cfi_def_cfa_offset 48
+	.cfi_offset 29, -48
+	.cfi_offset 30, -40
+	mov     x29, sp
+	.cfi_def_cfa_register 29
+	cmp     w4, w19
+	bge     .L1
+
+.L2:
+	.cfi_remember_state
+	bl      bar
+	ldp     x29, x30, [sp], 48
+	.cfi_def_cfa_register 31
+	.cfi_restore 29
+	.cfi_restore 30
+	.cfi_def_cfa_offset 0
+	ret
+.L1:
+	.cfi_restore_state
+	cbz     w3, .L2
+	ldp     x29, x30, [sp], 48
+	.cfi_def_cfa_register 31
+	.cfi_restore 29
+	.cfi_restore 30
+	.cfi_def_cfa_offset 0
+	ret
+	.cfi_endproc
+	.size   foo, .-foo
--- a/gas/testsuite/gas/scfi/aarch64/scfi-cfg-3.d
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-cfg-3.d
@@ -0,0 +1,32 @@
+#as: --scfi=experimental -W
+#objdump: -Wf
+#name: Synthesize CFI for cfg 3
+#...
+Contents of the .eh_frame section:
+
+
+0+0000 0+0010 0+0000 CIE
+  Version:               1
+  Augmentation:          "zR"
+  Code alignment factor: 4
+  Data alignment factor: -8
+  Return address column: 30
+  Augmentation data:     1b
+  DW_CFA_def_cfa: r31 \(sp\) ofs 0
+
+0+0014 0+0020 0+0018 FDE cie=00000000 pc=0+0000..0+002c
+  DW_CFA_advance_loc: 4 to 0+0004
+  DW_CFA_def_cfa_offset: 32
+  DW_CFA_offset: r29 \(x29\) at cfa-32
+  DW_CFA_offset: r30 \(x30\) at cfa-24
+  DW_CFA_advance_loc: 4 to 0+0008
+  DW_CFA_def_cfa_register: r29 \(x29\)
+  DW_CFA_advance_loc: 32 to 0+0028
+  DW_CFA_def_cfa_register: r31 \(sp\)
+  DW_CFA_restore: r29 \(x29\)
+  DW_CFA_restore: r30 \(x30\)
+  DW_CFA_def_cfa_offset: 0
+  DW_CFA_nop
+  DW_CFA_nop
+
+#pass
--- a/gas/testsuite/gas/scfi/aarch64/scfi-cfg-3.l
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-cfg-3.l
@@ -0,0 +1,2 @@
+.*Assembler messages:
+.*9: Warning: SCFI ignores most user-specified CFI directives
--- a/gas/testsuite/gas/scfi/aarch64/scfi-cfg-3.s
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-cfg-3.s
@@ -0,0 +1,34 @@
+# Testcase for cfg creation.
+# There is at least one bb here with a single GINSN_TYPE_SYMBOL instruction
+# for a user-defined label.  This ginsn is visited in the fallthrough path of
+# another bb.
+	.text
+	.global main
+	.type   main, %function
+main:
+	.cfi_startproc
+	stp     x29, x30, [sp, -32]!
+	.cfi_def_cfa_offset 32
+	.cfi_offset 29, -32
+	.cfi_offset 30, -24
+	mov     x29, sp
+	.cfi_def_cfa_register 29
+	cmp     w0, 0
+	bne     .L2
+#	ldr	x0, [sp, 24]
+#	bl	fclose
+	cmp     w0, 0
+	beq     .L3
+.L2:
+	mov     w0, 1
+	b       .L5
+.L3:
+	mov     w0, 0
+.L5:
+	ldp     x29, x30, [sp], 32
+	.cfi_def_cfa_register 31
+	.cfi_restore 29
+	.cfi_restore 30
+	.cfi_def_cfa_offset 0
+	ret
+	.cfi_endproc
--- a/gas/testsuite/gas/scfi/aarch64/scfi-cond-br-1.d
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-cond-br-1.d
@@ -0,0 +1,20 @@
+#as: --scfi=experimental -W
+#objdump: -Wf
+#name: Synthesize CFI for conditional br 1
+#...
+Contents of the .eh_frame section:
+
+
+0+0000 0+0010 0+0000 CIE
+  Version:               1
+  Augmentation:          "zR"
+  Code alignment factor: 4
+  Data alignment factor: -8
+  Return address column: 30
+  Augmentation data:     1b
+  DW_CFA_def_cfa: r31 \(sp\) ofs 0
+
+0+0014 0+0010 00000018 FDE cie=00000000 pc=0+0000..0+0010
+  DW_CFA_nop
+
+#pass
--- a/gas/testsuite/gas/scfi/aarch64/scfi-cond-br-1.l
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-cond-br-1.l
@@ -0,0 +1,2 @@
+.*Assembler messages:
+.*6: Warning: SCFI ignores most user-specified CFI directives
--- a/gas/testsuite/gas/scfi/aarch64/scfi-cond-br-1.s
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-cond-br-1.s
@@ -0,0 +1,13 @@
+	.text
+	.align  2
+	.global foo
+	.type   foo, %function
+foo:
+	.cfi_startproc
+	bge     .L10
+	ble     .L10
+	bne     .L10
+.L10:
+	ret
+	.cfi_endproc
+	.size   foo, .-foo
--- a/gas/testsuite/gas/scfi/aarch64/scfi-diag-1.l
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-diag-1.l
@@ -0,0 +1,2 @@
+.*Assembler messages:
+.*5: Warning: SCFI: ignored probable save/restore op with reg offset
--- a/gas/testsuite/gas/scfi/aarch64/scfi-diag-1.s
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-diag-1.s
@@ -0,0 +1,6 @@
+	.text
+	.globl  foo
+	.type   foo, @function
+foo:
+	str     x19, [sp, x1]
+	.size   foo, .-foo
--- a/gas/testsuite/gas/scfi/aarch64/scfi-ldrp-1.d
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-ldrp-1.d
@@ -0,0 +1,59 @@
+#as: --scfi=experimental -W
+#objdump: -Wf
+#name: Synthesize CFI for ldp ldr instructions
+#...
+Contents of the .eh_frame section:
+
+00000000 0+0010 00000000 CIE
+  Version:               1
+  Augmentation:          "zR"
+  Code alignment factor: 4
+  Data alignment factor: -8
+  Return address column: 30
+  Augmentation data:     1b
+  DW_CFA_def_cfa: r31 \(sp\) ofs 0
+
+00000014 0+0048 00000018 FDE cie=00000000 pc=0+0000..0+0040
+  DW_CFA_advance_loc: 4 to 0+0004
+  DW_CFA_def_cfa_offset: 128
+  DW_CFA_offset: r29 \(x29\) at cfa-128
+  DW_CFA_offset: r30 \(x30\) at cfa-120
+  DW_CFA_advance_loc: 4 to 0+0008
+  DW_CFA_def_cfa_register: r29 \(x29\)
+  DW_CFA_advance_loc: 4 to 0+000c
+  DW_CFA_offset: r19 \(x19\) at cfa-112
+  DW_CFA_offset: r20 \(x20\) at cfa-104
+  DW_CFA_advance_loc: 4 to 0+0010
+  DW_CFA_offset: r21 \(x21\) at cfa-96
+  DW_CFA_offset: r22 \(x22\) at cfa-88
+  DW_CFA_advance_loc: 4 to 0+0014
+  DW_CFA_offset: r23 \(x23\) at cfa-80
+  DW_CFA_offset: r24 \(x24\) at cfa-72
+  DW_CFA_advance_loc: 4 to 0+0018
+  DW_CFA_offset: r25 \(x25\) at cfa-64
+  DW_CFA_offset: r26 \(x26\) at cfa-56
+  DW_CFA_advance_loc: 4 to 0+001c
+  DW_CFA_offset: r27 \(x27\) at cfa-48
+  DW_CFA_advance_loc: 8 to 0+0024
+  DW_CFA_def_cfa_register: r31 \(sp\)
+  DW_CFA_advance_loc: 4 to 0+0028
+  DW_CFA_restore: r19 \(x19\)
+  DW_CFA_restore: r20 \(x20\)
+  DW_CFA_advance_loc: 4 to 0+002c
+  DW_CFA_restore: r21 \(x21\)
+  DW_CFA_restore: r22 \(x22\)
+  DW_CFA_advance_loc: 4 to 0+0030
+  DW_CFA_restore: r23 \(x23\)
+  DW_CFA_restore: r24 \(x24\)
+  DW_CFA_advance_loc: 4 to 0+0034
+  DW_CFA_restore: r25 \(x25\)
+  DW_CFA_restore: r26 \(x26\)
+  DW_CFA_advance_loc: 4 to 0+0038
+  DW_CFA_restore: r27 \(x27\)
+  DW_CFA_advance_loc: 4 to 0+003c
+  DW_CFA_restore: r29 \(x29\)
+  DW_CFA_restore: r30 \(x30\)
+  DW_CFA_def_cfa_offset: 0
+  DW_CFA_nop
+
+#pass
--- a/gas/testsuite/gas/scfi/aarch64/scfi-ldrp-1.l
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-ldrp-1.l
@@ -0,0 +1,2 @@
+.*Assembler messages:
+.*8: Warning: SCFI ignores most user-specified CFI directives
--- a/gas/testsuite/gas/scfi/aarch64/scfi-ldrp-1.s
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-ldrp-1.s
@@ -0,0 +1,52 @@
+# Testcase for various ldp / ldr instructions.
+# This test also serves for checking callee-saved regs.
+	.text
+	.align  2
+	.global foo
+	.type   foo, %function
+foo:
+	.cfi_startproc
+	stp     x29, x30, [sp, -128]!
+	.cfi_def_cfa_offset 128
+	.cfi_offset 29, -128
+	.cfi_offset 30, -120
+	mov     x29, sp
+	.cfi_def_cfa_register 29
+	stp     x19, x20, [sp, 16]
+	.cfi_offset 19, -112
+	.cfi_offset 20, -104
+	stp     x21, x22, [sp, 32]
+	.cfi_offset 21, -96
+	.cfi_offset 22, -88
+	stp     x23, x24, [sp, 48]
+	.cfi_offset 23, -80
+	.cfi_offset 24, -72
+	stp     x25, x26, [sp, 64]
+	.cfi_offset 25, -64
+	.cfi_offset 26, -56
+	str     x27, [sp, 80]
+	.cfi_offset 27, -48
+	mov     w0, 0
+	mov     sp, x29
+	.cfi_def_cfa_register 31
+	ldp     x19, x20, [sp, 16]
+	.cfi_restore 19
+	.cfi_restore 20
+	ldp     x21, x22, [sp, 32]
+	.cfi_restore 21
+	.cfi_restore 22
+	ldp     x23, x24, [sp, 48]
+	.cfi_restore 23
+	.cfi_restore 24
+	ldp     x25, x26, [sp, 64]
+	.cfi_restore 25
+	.cfi_restore 26
+	ldr     x27, [sp, 80]
+	.cfi_restore 27
+	ldp     x29, x30, [sp], 128
+	.cfi_restore 29
+	.cfi_restore 30
+	.cfi_def_cfa_offset 0
+	ret
+	.cfi_endproc
+	.size   foo, .-foo
--- a/gas/testsuite/gas/scfi/aarch64/scfi-ldrp-2.d
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-ldrp-2.d
@@ -0,0 +1,33 @@
+#as: --scfi=experimental -W
+#objdump: -Wf
+#name: Synthesize CFI for ldr insns 2
+#...
+Contents of the .eh_frame section:
+
+00000000 0+0010 00000000 CIE
+  Version:               1
+  Augmentation:          "zR"
+  Code alignment factor: 4
+  Data alignment factor: -8
+  Return address column: 30
+  Augmentation data:     1b
+  DW_CFA_def_cfa: r31 \(sp\) ofs 0
+
+00000014 0+[0-9a-f]+ 00000018 FDE cie=00000000 pc=0+0000..0+0018
+  DW_CFA_advance_loc: 4 to 0+0004
+  DW_CFA_def_cfa_offset: 128
+  DW_CFA_offset: r29 \(x29\) at cfa-128
+  DW_CFA_offset: r30 \(x30\) at cfa-120
+  DW_CFA_advance_loc: 4 to 0+0008
+  DW_CFA_def_cfa_register: r29 \(x29\)
+  DW_CFA_advance_loc: 4 to 0+000c
+  DW_CFA_def_cfa_register: r31 \(sp\)
+  DW_CFA_advance_loc: 4 to 0+0010
+  DW_CFA_restore: r29 \(x29\)
+  DW_CFA_def_cfa_offset: 120
+  DW_CFA_advance_loc: 4 to 0+0014
+  DW_CFA_restore: r30 \(x30\)
+  DW_CFA_def_cfa_offset: 0
+  DW_CFA_nop
+
+#pass
--- a/gas/testsuite/gas/scfi/aarch64/scfi-ldrp-2.l
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-ldrp-2.l
@@ -0,0 +1,2 @@
+.*Assembler messages:
+.*7: Warning: SCFI ignores most user-specified CFI directives
--- a/gas/testsuite/gas/scfi/aarch64/scfi-ldrp-2.s
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-ldrp-2.s
@@ -0,0 +1,26 @@
+# Testcase for various ldp / ldr instructions
+	.text
+	.align  2
+	.global foo
+	.type   foo, %function
+foo:
+	.cfi_startproc
+	stp     x29, x30, [sp, -128]!
+	.cfi_def_cfa_offset 128
+	.cfi_offset 29, -128
+	.cfi_offset 30, -120
+	mov     x29, sp
+	.cfi_def_cfa_register 29
+	mov     sp, x29
+	.cfi_def_cfa_register 31
+# Post-indexed ldr
+	ldr     x29, [sp], 8
+	.cfi_restore 29
+	.cfi_def_cfa_offset 120
+# Post-indexed ldr
+	ldr     x30, [sp], 120
+	.cfi_restore 30
+	.cfi_def_cfa_offset 0
+	ret
+	.cfi_endproc
+	.size   foo, .-foo
--- a/gas/testsuite/gas/scfi/aarch64/scfi-strp-1.d
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-strp-1.d
@@ -0,0 +1,39 @@
+#as: --scfi=experimental -W
+#objdump: -Wf
+#name: Synthesize CFI for str stp insns 1
+#...
+Contents of the .eh_frame section:
+
+00000000 0+0010 00000000 CIE
+  Version:               1
+  Augmentation:          "zR"
+  Code alignment factor: 4
+  Data alignment factor: -8
+  Return address column: 30
+  Augmentation data:     1b
+  DW_CFA_def_cfa: r31 \(sp\) ofs 0
+
+00000014 0+0030 00000018 FDE cie=00000000 pc=0+0000..0+002c
+  DW_CFA_advance_loc: 4 to 0+0004
+  DW_CFA_def_cfa_offset: 128
+  DW_CFA_offset: r29 \(x29\) at cfa-128
+  DW_CFA_offset: r30 \(x30\) at cfa-120
+  DW_CFA_advance_loc: 4 to 0+0008
+  DW_CFA_def_cfa_register: r29 \(x29\)
+  DW_CFA_advance_loc: 4 to 0+000c
+  DW_CFA_offset: r19 \(x19\) at cfa-112
+  DW_CFA_offset: r20 \(x20\) at cfa-104
+  DW_CFA_advance_loc: 4 to 0+0010
+  DW_CFA_offset: r21 \(x21\) at cfa-96
+  DW_CFA_offset: r22 \(x22\) at cfa-88
+  DW_CFA_advance_loc: 4 to 0+0014
+  DW_CFA_offset: r23 \(x23\) at cfa-80
+  DW_CFA_offset: r24 \(x24\) at cfa-72
+  DW_CFA_advance_loc: 4 to 0+0018
+  DW_CFA_offset: r25 \(x25\) at cfa-64
+  DW_CFA_offset: r26 \(x26\) at cfa-56
+  DW_CFA_advance_loc: 4 to 0+001c
+  DW_CFA_offset: r27 \(x27\) at cfa-48
+  DW_CFA_nop
+
+#pass
--- a/gas/testsuite/gas/scfi/aarch64/scfi-strp-1.l
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-strp-1.l
@@ -0,0 +1,2 @@
+.*Assembler messages:
+.*6: Warning: SCFI ignores most user-specified CFI directives
--- a/gas/testsuite/gas/scfi/aarch64/scfi-strp-1.s
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-strp-1.s
@@ -0,0 +1,37 @@
+## Testcase with a variety of str/stp instructions
+	.text
+	.globl  foo
+	.type   foo, @function
+foo:
+	.cfi_startproc
+# Pre-indexed addressing is like offset addressing, except that
+# the base pointer is updated as a result of the instruction.
+	stp     x29, x30, [sp, -128]!
+	.cfi_def_cfa_offset 128
+	.cfi_offset 29, -128
+	.cfi_offset 30, -120
+	mov     x29, sp
+	.cfi_def_cfa_register 29
+# Offset addressing mode is when ann offset can be applied optionally to the
+# base address.
+	stp     x19, x20, [sp, 16]
+	.cfi_offset 19, -112
+	.cfi_offset 20, -104
+	stp     x21, x22, [sp, 32]
+	.cfi_offset 21, -96
+	.cfi_offset 22, -88
+	stp     x23, x24, [sp, 48]
+	.cfi_offset 23, -80
+	.cfi_offset 24, -72
+	stp     x25, x26, [sp, 64]
+	.cfi_offset 25, -64
+	.cfi_offset 26, -56
+	str     x27, [sp, 80]
+	.cfi_offset 27, -48
+# Stores non callee-saved register on stack.
+	str     w0, [x29, 124]
+	str     wzr, [x29, 120]
+	str     w0, [x29, 120]
+	ret
+	.cfi_endproc
+	.size   foo, .-foo
--- a/gas/testsuite/gas/scfi/aarch64/scfi-strp-2.d
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-strp-2.d
@@ -0,0 +1,35 @@
+#as: --scfi=experimental -W
+#objdump: -Wf
+#name: Synthesize CFI for str insns 2
+#...
+Contents of the .eh_frame section:
+
+00000000 0+0010 00000000 CIE
+  Version:               1
+  Augmentation:          "zR"
+  Code alignment factor: 4
+  Data alignment factor: -8
+  Return address column: 30
+  Augmentation data:     1b
+  DW_CFA_def_cfa: r31 \(sp\) ofs 0
+
+00000014 0+0028 00000018 FDE cie=00000000 pc=0+0000..0+001c
+  DW_CFA_advance_loc: 4 to 0+0004
+  DW_CFA_def_cfa_offset: 128
+  DW_CFA_offset: r29 \(x29\) at cfa-128
+  DW_CFA_offset: r30 \(x30\) at cfa-120
+  DW_CFA_advance_loc: 4 to 0+0008
+  DW_CFA_def_cfa_register: r29 \(x29\)
+  DW_CFA_advance_loc: 4 to 0+000c
+  DW_CFA_offset: r27 \(x27\) at cfa-128
+  DW_CFA_advance_loc: 4 to 0+0010
+  DW_CFA_def_cfa_register: r31 \(sp\)
+  DW_CFA_advance_loc: 4 to 0+0014
+  DW_CFA_restore: r29 \(x29\)
+  DW_CFA_def_cfa_offset: 120
+  DW_CFA_advance_loc: 4 to 0+0018
+  DW_CFA_restore: r30 \(x30\)
+  DW_CFA_def_cfa_offset: 0
+  DW_CFA_nop
+
+#pass
--- a/gas/testsuite/gas/scfi/aarch64/scfi-strp-2.l
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-strp-2.l
@@ -0,0 +1,2 @@
+.*Assembler messages:
+.*7: Warning: SCFI ignores most user-specified CFI directives
--- a/gas/testsuite/gas/scfi/aarch64/scfi-strp-2.s
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-strp-2.s
@@ -0,0 +1,30 @@
+# Testcase for a variety of stp/str including a post-indexed store
+	.text
+	.align  2
+	.global foo
+	.type   foo, %function
+foo:
+	.cfi_startproc
+	stp     x29, x30, [sp, -128]!
+	.cfi_def_cfa_offset 128
+	.cfi_offset 29, -128
+	.cfi_offset 30, -120
+	mov     x29, sp
+	.cfi_def_cfa_register 29
+# post-indexed store, a stack corrupting one which over-writes
+# x29!  Only for testing purposes for now
+# This does not generate a .cfi_def_cfa_offset 208 because
+# CFA is REG_FP based
+	str     x27, [sp], 80
+	.cfi_offset 27, -128
+	mov     sp, x29
+	.cfi_def_cfa_register 31
+	ldr     x29, [sp], 8
+	.cfi_restore 29
+	.cfi_def_cfa_offset 120
+	ldr     x30, [sp], 120
+	.cfi_restore 30
+	.cfi_def_cfa_offset 0
+	ret
+	.cfi_endproc
+	.size   foo, .-foo
--- a/gas/testsuite/gas/scfi/aarch64/scfi-unsupported-1.l
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-unsupported-1.l
@@ -0,0 +1,4 @@
+.*Assembler messages:
+.*7: Warning: SCFI ignores most user-specified CFI directives
+.*9: Error: SCFI: unsupported stack manipulation pattern
+.*31: Error: SCFI: forward pass failed for func 'foo'
--- a/gas/testsuite/gas/scfi/aarch64/scfi-unsupported-1.s
+++ b/gas/testsuite/gas/scfi/aarch64/scfi-unsupported-1.s
@@ -0,0 +1,31 @@
+# Testcase where immediate used for stack allocation is a wide
+# one.  Since SCFI does not currently have any data-flow
+# capabilities, this is currently not supported.
+	.global	foo
+	.type	foo, %function
+foo:
+	.cfi_startproc
+	mov	x16, 4384
+	sub	sp, sp, x16
+	.cfi_def_cfa_offset 4384
+	stp	x29, x30, [sp]
+	.cfi_offset 29, -4384
+	.cfi_offset 30, -4376
+	mov	x29, sp
+	str	x0, [sp, 24]
+	str	x1, [sp, 16]
+	add	x0, sp, 4096
+	add	x0, x0, 112
+	bl	bar
+.L1:
+	str	xzr, [sp, 4376]
+.L2:
+	ldp	x29, x30, [sp]
+	mov	x16, 4384
+	add	sp, sp, x16
+	.cfi_restore 29
+	.cfi_restore 30
+	.cfi_def_cfa_offset 0
+	ret
+	.cfi_endproc
+	.size	foo, .-foo
--- a/gas/testsuite/gas/scfi/x86_64/ginsn-cofi-1.l
+++ b/gas/testsuite/gas/scfi/x86_64/ginsn-cofi-1.l
@@ -1,8 +1,7 @@
 .*: Assembler messages:
-.*:20: Error: untraceable control flow for func 'foo'
+.*:24: Error: untraceable control flow for func 'foo'
 GAS LISTING .*

-
   1              	# Testcase with a variety of "change of flow instructions"
   2              	#
   3              	# This test does not have much going on wrt synthesis of CFI;
@@ -22,17 +21,29 @@ GAS LISTING .*
  12              	ginsn: JMP %r0, 
  13 \?\?\?\? 41FFD0   		call    \*%r8
  13              	ginsn: CALL
-  14 \?\?\?\? 67E305   		jecxz   .L179
-  14              	ginsn: JCC 
-  15 \?\?\?\? FF6730   		jmp     \*48\(%rdi\)
-  15              	ginsn: JMP %r5, 
-  16 \?\?\?\? 7000     		jo      .L179
+  14 \?\?\?\? FF14C500 		call    \*cost_arr\(,%rax,8\)
+  14      000000
+  14              	ginsn: CALL
+  15 \?\?\?\? FF142500 		call    \*symbol\+1
+  15      000000
+  15              	ginsn: CALL
+  16 \?\?\?\? 67E313   		jecxz   .L179
  16              	ginsn: JCC 
-  17              	.L179:
-  17              	ginsn: SYM .L179
-  18 \?\?\?\? C3       		ret
-  18              	ginsn: RET
-  19              	.LFE0:
-  19              	ginsn: SYM .LFE0
-  20              		.size   foo, .-foo
-  20              	ginsn: SYM FUNC_END
+  17 \?\?\?\? FF6730   		jmp     \*48\(%rdi\)
+  17              	ginsn: JMP %r5, 
+  18 \?\?\?\? FF24C500 		jmp     \*cost_arr\(,%rax,8\)
+  18      000000
+  18              	ginsn: JMP %r0, 
+  19 \?\?\?\? FF242500 		jmp     \*symbol\+1
+  19      000000
+  19              	ginsn: JMP %r4, 
+  20 \?\?\?\? 7000     		jo      .L179
+  20              	ginsn: JCC 
+  21              	.L179:
+  21              	ginsn: SYM .L179
+  22 \?\?\?\? C3       		ret
+  22              	ginsn: RET
+  23              	.LFE0:
+  23              	ginsn: SYM .LFE0
+  24              		.size   foo, .-foo
+  24              	ginsn: SYM FUNC_END
--- a/gas/testsuite/gas/scfi/x86_64/ginsn-cofi-1.s
+++ b/gas/testsuite/gas/scfi/x86_64/ginsn-cofi-1.s
@@ -11,8 +11,12 @@ foo:
 	loop    foo
 	notrack jmp     *%rax
 	call    *%r8
+	call    *cost_arr(,%rax,8)
+	call    *symbol+1
 	jecxz   .L179
 	jmp     *48(%rdi)
+	jmp     *cost_arr(,%rax,8)
+	jmp     *symbol+1
 	jo      .L179
 .L179:
 	ret
--- a/gas/testsuite/gas/scfi/x86_64/scfi-cfg-4.d
+++ b/gas/testsuite/gas/scfi/x86_64/scfi-cfg-4.d
@@ -0,0 +1,43 @@
+#as: --scfi=experimental -W
+#as:
+#objdump: -Wf
+#name: Synthesize CFI in presence of control flow 4
+#...
+Contents of the .eh_frame section:
+
+00000000 0+0014 0+0000 CIE
+  Version:               1
+  Augmentation:          "zR"
+  Code alignment factor: 1
+  Data alignment factor: -8
+  Return address column: 16
+  Augmentation data:     1b
+  DW_CFA_def_cfa: r7 \(rsp\) ofs 8
+  DW_CFA_offset: r16 \(rip\) at cfa-8
+  DW_CFA_nop
+  DW_CFA_nop
+
+0+0018 0+002c 0+001c FDE cie=00000000 pc=0000000000000000..0000000000000045
+  DW_CFA_advance_loc: 1 to 0000000000000001
+  DW_CFA_def_cfa_offset: 16
+  DW_CFA_offset: r3 \(rbx\) at cfa-16
+  DW_CFA_advance_loc: 6 to 0000000000000007
+  DW_CFA_def_cfa_offset: 32
+  DW_CFA_advance_loc: 15 to 0000000000000016
+  DW_CFA_remember_state
+  DW_CFA_advance_loc: 4 to 000000000000001a
+  DW_CFA_def_cfa_offset: 16
+  DW_CFA_advance_loc: 1 to 000000000000001b
+  DW_CFA_restore: r3 \(rbx\)
+  DW_CFA_def_cfa_offset: 8
+  DW_CFA_advance_loc: 1 to 000000000000001c
+  DW_CFA_restore_state
+  DW_CFA_advance_loc: 35 to 000000000000003f
+  DW_CFA_def_cfa_offset: 16
+  DW_CFA_advance_loc: 1 to 0000000000000040
+  DW_CFA_restore: r3 \(rbx\)
+  DW_CFA_def_cfa_offset: 8
+  DW_CFA_nop
+#...
+
+#pass
--- a/gas/testsuite/gas/scfi/x86_64/scfi-cfg-4.l
+++ b/gas/testsuite/gas/scfi/x86_64/scfi-cfg-4.l
@@ -0,0 +1,2 @@
+.*Assembler messages:
+.*5: Warning: SCFI ignores most user-specified CFI directives
--- a/gas/testsuite/gas/scfi/x86_64/scfi-cfg-4.s
+++ b/gas/testsuite/gas/scfi/x86_64/scfi-cfg-4.s
@@ -0,0 +1,42 @@
+	.text
+	.globl  foo_handler
+	.type   foo_handler, @function
+foo_handler:
+	.cfi_startproc
+	pushq   %rbx
+	.cfi_def_cfa_offset 16
+	.cfi_offset %rbx, -16
+	movl    %esi, %ebx
+	subq    $16, %rsp
+	.cfi_def_cfa_offset 32
+	movl    current_style(%rip), %eax
+	cmpl    $-1, %eax
+	je      .L12
+	testb   $4, %al
+	jne     .L13
+.L1:
+	.cfi_remember_state
+	addq    $16, %rsp
+	.cfi_def_cfa_offset 16
+	popq    %rbx
+	.cfi_restore %rbx
+	.cfi_def_cfa_offset 8
+	ret
+.L13:
+	.cfi_restore_state
+	movq    %rdi, 8(%rsp)
+	call    foo_handler_v2
+	testq   %rax, %rax
+	jne     .L1
+	movl    current_style(%rip), %eax
+	movq    8(%rsp), %rdi
+	jmp     .L3
+.L12:
+	addq    $16, %rsp
+	.cfi_def_cfa_offset 16
+	popq    %rbx
+	.cfi_restore %rbx
+	.cfi_def_cfa_offset 8
+	jmp     xstrdup
+	.cfi_endproc
+	.size   foo_handler, .-foo_handler
--- a/gas/testsuite/gas/scfi/x86_64/scfi-cfg-5.d
+++ b/gas/testsuite/gas/scfi/x86_64/scfi-cfg-5.d
@@ -0,0 +1,39 @@
+#as: --scfi=experimental -W
+#as:
+#objdump: -Wf
+#name: Synthesize CFI in presence of control flow 5
+#...
+Contents of the .eh_frame section:
+
+00000000 0+0014 0+0000 CIE
+  Version:               1
+  Augmentation:          "zR"
+  Code alignment factor: 1
+  Data alignment factor: -8
+  Return address column: 16
+  Augmentation data:     1b
+  DW_CFA_def_cfa: r7 \(rsp\) ofs 8
+  DW_CFA_offset: r16 \(rip\) at cfa-8
+  DW_CFA_nop
+  DW_CFA_nop
+
+0+0018 0+002c 0000001c FDE cie=00000000 pc=0+0000..0+0017
+  DW_CFA_advance_loc: 1 to 0+0001
+  DW_CFA_def_cfa_offset: 16
+  DW_CFA_offset: r6 \(rbp\) at cfa-16
+  DW_CFA_advance_loc: 3 to 0+0004
+  DW_CFA_def_cfa_register: r6 \(rbp\)
+  DW_CFA_advance_loc: 5 to 0+0009
+  DW_CFA_remember_state
+  DW_CFA_advance_loc: 6 to 0+000f
+  DW_CFA_def_cfa_register: r7 \(rsp\)
+  DW_CFA_restore: r6 \(rbp\)
+  DW_CFA_def_cfa_offset: 8
+  DW_CFA_advance_loc: 1 to 0+0010
+  DW_CFA_restore_state
+  DW_CFA_advance_loc: 6 to 0+0016
+  DW_CFA_def_cfa_register: r7 \(rsp\)
+  DW_CFA_restore: r6 \(rbp\)
+  DW_CFA_def_cfa_offset: 8
+
+#pass
--- a/gas/testsuite/gas/scfi/x86_64/scfi-cfg-5.l
+++ b/gas/testsuite/gas/scfi/x86_64/scfi-cfg-5.l
@@ -0,0 +1,2 @@
+.*Assembler messages:
+.*5: Warning: SCFI ignores most user-specified CFI directives
--- a/gas/testsuite/gas/scfi/x86_64/scfi-cfg-5.s
+++ b/gas/testsuite/gas/scfi/x86_64/scfi-cfg-5.s
@@ -0,0 +1,32 @@
+	.text
+	.globl foo
+	.type foo, @function
+foo:
+	.cfi_startproc
+	push  %rbp
+	.cfi_def_cfa_offset 16
+	.cfi_offset %rbp, -16
+	mov   %rsp, %rbp
+	.cfi_def_cfa_register %rbp
+	cmpl  $-1, %eax
+	jne .L1
+.L2:
+	.cfi_remember_state
+	call bar
+	pop  %rbp
+	.cfi_def_cfa_register %rsp
+	.cfi_restore %rbp
+	.cfi_def_cfa_offset 8
+	ret
+
+.L1:
+	.cfi_restore_state
+	testq %rax, %rax
+	je .L2
+	pop %rbp
+	.cfi_def_cfa_register %rsp
+	.cfi_restore %rbp
+	.cfi_def_cfa_offset 8
+	ret
+	.cfi_endproc
+	.size foo,.-foo
--- a/gas/testsuite/gas/scfi/x86_64/scfi-unsupported-insn-1.l
+++ b/gas/testsuite/gas/scfi/x86_64/scfi-unsupported-insn-1.l
@@ -1,7 +1,8 @@
 .*Assembler messages:
-.*7: Error: SCFI: unsupported APX op 0x8f may cause incorrect CFI
-.*8: Error: SCFI: unsupported APX op 0x8f may cause incorrect CFI
-.*9: Error: SCFI: unsupported APX op 0xff may cause incorrect CFI
-.*10: Error: SCFI: unsupported APX op 0xff may cause incorrect CFI
-.*11: Error: SCFI: unsupported APX op 0x11 may cause incorrect CFI
+.*7: Error: SCFI: unhandled op 0x8f may cause incorrect CFI
+.*8: Error: SCFI: unhandled op 0x8f may cause incorrect CFI
+.*9: Error: SCFI: unhandled op 0xff may cause incorrect CFI
+.*10: Error: SCFI: unhandled op 0xff may cause incorrect CFI
 .*13: Error: SCFI: hand-crafting instructions not supported
+.*11: Error: SCFI: unsupported stack manipulation pattern
+.*16: Error: SCFI: forward pass failed for func 'foo'
--- a/gas/testsuite/gas/scfi/x86_64/scfi-x86-64.exp
+++ b/gas/testsuite/gas/scfi/x86_64/scfi-x86-64.exp
@@ -80,6 +80,10 @@ if  { ([istarget "x86_64-*-*"] && ![istarget "x86_64-*-linux*-gnux32"]) } then {
    run_list_test "scfi-cfg-2" "--scfi=experimental --warn"
    run_dump_test "scfi-cfg-3"
    run_list_test "scfi-cfg-3" "--scfi=experimental --warn"
+    run_dump_test "scfi-cfg-4"
+    run_list_test "scfi-cfg-4" "--scfi=experimental --warn"
+    run_dump_test "scfi-cfg-5"
+    run_list_test "scfi-cfg-5" "--scfi=experimental --warn"
    run_dump_test "scfi-asm-marker-1"
    run_list_test "scfi-asm-marker-1" "--scfi=experimental --warn"
    run_dump_test "scfi-asm-marker-2"
Author	SHA1	Message	Date
Indu Bhagat	eeadfb158b	gas: x86: fix code comments and other nits ChangeLog: * gas/config/tc-i386.c	2024-03-28 16:55:50 -07:00
Indu Bhagat	6ea6536f01	gas: x86: ginsn: adapt the APX insn handling A review comment on the SCFI V4 series was to bail out on APX instructions differently: Currently, GAS bails out at the mere sight of an APX instruction when --scfi=experimental is in effect; this is implemented in form of an early exit from x86_ginsn_new (). It is preferable to not have to handle APX instructions explicitly like that with an early exit, but rather to use the existing infrastructure in the x86_ginsn_new () function to bail out only if the APX insn affects SCFI correctness. FIXME - 1. There remains an outstanding issue with adcx etc ops 2. Add tests once above is fixed gas/ * config/tc-i386.c (ginsn_opsize_prefix_p): Rename and adjust to be ginsn_implicitstackop_opsize16_p instead. (x86_ginsn_enter): Use the new function. (x86_ginsn_leave): Likewise. (x86_ginsn_new): Likewise. Also remove the stub for early exit for APX instructions. gas/testsuite/ * gas/scfi/x86_64/scfi-unsupported-insn-1.l:	2024-03-28 16:55:50 -07:00
Indu Bhagat	977da52111	gas: x86: ginsn: handle previously missed indirect call and jmp ops Some flavors of indirect call and jmp instructions were not being handled earlier, leading to a GAS error (#1): (#1) "Error: SCFI: unhandled op 0xff may cause incorrect CFI" Not handling jmp/call (direct or indirect) ops is an error (as shown above) because SCFI needs an accurate CFG to synthesize CFI correctly. Recall that the presence of indirect jmp/call, however, does make the CFG ineligible for SCFI. In other words, generating the ginsns for them now, will eventually cause SCFI to bail out later with an error (#2) anyway: (#2) "Error: untraceable control flow for func 'XXX'" The first error (#1) gives the impression of missing functionality in GAS. So, it seems cleaner to synthesize a GINSN_TYPE_JUMP / GINSN_TYPE_CALL accurately in the backend, and let SCFI machinery complain with the error as expected. The handling for these indirect jmp/call instructions is similar, so reuse the code by carving out a function for the same. Adjust the testcase to include the now handled jmp/call instructions as well. gas/ * config/tc-i386.c (x86_ginsn_indirect_jump_call): New function. (x86_ginsn_new): Refactor out functionality to above. gas/testsuite/ * gas/scfi/x86_64/ginsn-cofi-1.l: Adjust the output. * gas/scfi/x86_64/ginsn-cofi-1.s: Add further varieties of jmp/call opcodes.	2024-03-28 16:55:50 -07:00
Indu Bhagat	0d12d72fc6	gas: scfi: bugfixes for SCFI state propagation There are two state propagation functions in SCFI machinery - forward and backward flow. The patch addresses two issues: - In forward_flow_scfi_state (), the state being compared in forward flow must be that at the exit of a prev bb and that at the entry of the next bb. The variable holding the state to be compared was previously (erroneously) stale. - In cmp_scfi_state (), the assumption that two different control flows, leading to the same basic block, cannot have a mismatched notion of CFA base register, is not true. Remove the assertion and instead return err if mismatch. Fixing these issues helps correctly synthesize CFI, when previously SCFI was erroring out for an otherwise valid input asm. gas/ * scfi.c (cmp_scfi_state): Remove assertion and return mismatch in return value as applicable. (forward_flow_scfi_state): Update state object to be the same as the exit state of the prev bb before comparing. gas/testsuite/ * gas/scfi/x86_64/scfi-x86-64.exp: Add new test. * gas/scfi/x86_64/scfi-cfg-5.d: New test. * gas/scfi/x86_64/scfi-cfg-5.l: New test. * gas/scfi/x86_64/scfi-cfg-5.s: New test.	2024-03-28 16:55:50 -07:00
Indu Bhagat	d412bdce32	gas: gcfg: add_bb_at_ginsn must return root_bb A GCFG (ginsn control flow graph) is created for SCFI purposes in GAS. The existing GCFG creation process was ignoring some paths. add_bb_at_ginsn () is a recursive function which should return the root of the added basic blocks. This property was being violated in some traversals, e.g., where a taken path involving a sequence of a few basic blocks eventually culminated in a GINSN_TYPE_RETURN instruction. This patch fixes the issue by keeping an explicit variable root_bb to memorize the bb to be returned. Next, find_or_make_bb () must either create or find the bb with the first ginsn as the provided ginsn. Add a few assertions to ensure health of the cfg creation process. Note that the testcase, in its current shape, is not fit for catching regressions for the issue at hand. Although the testcase does exercise the updated code path, the testcase passes even without the current fix, because the added edge in this specific testcase does not alter the synthesized CFI. (The missing edge is the fallthrough edge of the conditional branch "jne .L13" in the testcase.) Using a manual gcfg_print (), one can see the missing edge without the fix. Lets keep the testcase for now, until there is a better way to test the GCFG for this issue (e.g., either by dumping the GCFG in textual format, or a case when the missing edge does cause wrong synthesized CFI). gas/ * ginsn.c (bb_add_edge): Fix a code comment. (find_bb): Likewise. (find_or_make_bb): Add new assertions to ensure health of cfg creation process. (add_bb_at_ginsn): Keep reference to the root_bb and return it. gas/testsuite/ * gas/scfi/x86_64/scfi-x86-64.exp: Add new test. * gas/scfi/x86_64/scfi-cfg-4.d: New test. * gas/scfi/x86_64/scfi-cfg-4.l: New test. * gas/scfi/x86_64/scfi-cfg-4.s: New test.	2024-03-28 16:55:50 -07:00
Indu Bhagat	f7a2f944bb	gas: aarch64: testsuite: add new tests for SCFI Similar to the x86_64 testcases, some .s files contain the corresponding CFI directives. This helps in validating the synthesized CFI by running those tests with and without the --scfi=experimental command line option. Apart from the existing scfi-diag-.s tests in gas/scfi/x86_64 directory, the newly added scfi-diag-1.s in this patch highlights an aarch64-specific diagnostic: "Warning: SCFI: ignored probable save/restore op with reg offset" Additionally, some testcases are added to showcase the (currently) unsupported patterns, e.g., scfi-unsupported-1.s mov x16, 4384 sub sp, sp, x16 gas/testsuite/: gas/scfi/README: Update comment to include aarch64. * gas/scfi/aarch64/scfi-aarch64.exp: New file. * gas/scfi/aarch64/ginsn-cofi-1.l: New test. * gas/scfi/aarch64/ginsn-cofi-1.s: New test. * gas/scfi/aarch64/ginsn-ldst-1.l: New test. * gas/scfi/aarch64/ginsn-ldst-1.s: New test. * gas/scfi/aarch64/scfi-cb-1.d: New test. * gas/scfi/aarch64/scfi-cb-1.l: New test. * gas/scfi/aarch64/scfi-cb-1.s: New test. * gas/scfi/aarch64/scfi-cfg-1.d: New test. * gas/scfi/aarch64/scfi-cfg-1.l: New test. * gas/scfi/aarch64/scfi-cfg-1.s: New test. * gas/scfi/aarch64/scfi-cfg-2.d: New test. * gas/scfi/aarch64/scfi-cfg-2.l: New test. * gas/scfi/aarch64/scfi-cfg-2.s: New test. * gas/scfi/aarch64/scfi-cfg-3.d: New test. * gas/scfi/aarch64/scfi-cfg-3.l: New test. * gas/scfi/aarch64/scfi-cfg-3.s: New test. * gas/scfi/aarch64/scfi-cond-br-1.d: New test. * gas/scfi/aarch64/scfi-cond-br-1.l: New test. * gas/scfi/aarch64/scfi-cond-br-1.s: New test. * gas/scfi/aarch64/scfi-diag-1.l: New test. * gas/scfi/aarch64/scfi-diag-1.s: New test. * gas/scfi/aarch64/scfi-ldrp-1.d: New test. * gas/scfi/aarch64/scfi-ldrp-1.l: New test. * gas/scfi/aarch64/scfi-ldrp-1.s: New test. * gas/scfi/aarch64/scfi-ldrp-2.d: New test. * gas/scfi/aarch64/scfi-ldrp-2.l: New test. * gas/scfi/aarch64/scfi-ldrp-2.s: New test. * gas/scfi/aarch64/scfi-strp-1.d: New test. * gas/scfi/aarch64/scfi-strp-1.l: New test. * gas/scfi/aarch64/scfi-strp-1.s: New test. * gas/scfi/aarch64/scfi-strp-2.d: New test. * gas/scfi/aarch64/scfi-strp-2.l: New test. * gas/scfi/aarch64/scfi-strp-2.s: New test.	2024-03-28 16:55:49 -07:00
Indu Bhagat	4e97c9dcfc	gas: aarch64: add experimental support for SCFI For synthesizing CFI (SCFI) for hand-written asm, the SCFI machinery in GAS works on the generic GAS insns (ginsns). This patch adds support in the aarch64 backend to create ginsns for the following set of machine instructions, which are necessary to process to ensure SCFI correctness: - Any potential register saves and unsaves. This implies the need to process many iclasses involving str, ldr, stp, ldp. - Any change of flow instructions, including all conditional and unconditional branches, call (bl, blr) and return. - Any instruction that could affect the two registers of interest: REG_SP, REG_FP. This set includes all pre-indexed and post-indexed memory operations, with writeback, on the stack. SCFI is enabled for ELF targets only. Apart from creating ginsn, we also add functionality in the backend to detect dynamically if an instruction of interest may have been skipped. Such a check is added with an intent to also capture changes in the ISA which may otherwise render incorrect SCFI results. The current SCFI machinery does not currently synthesize the PAC-related aarch64-specific CFI directives: .cfi_b_key_frame. The support for this is planned for near future. gas/ * config/tc-aarch64.c (GINSN_DW2_REGNUM_R1_DUMMY): (aarch64_scfi_callee_saved_p): (ginsn_dw2_regnum): (aarch64_ginsn_addsub): (aarch64_ginsn_ldstp): (aarch64_ginsn_ldstr): (aarch64_ginsn_jump): (aarch64_ginsn_jump_cond): (aarch64_ginsn_mov): (aarch64_ginsn_safe_to_skip_p): (AARCH64_GINSN_UNHANDLED_NONE): (AARCH64_GINSN_UNHANDLED_DEST_REG): (AARCH64_GINSN_UNHANDLED_CFG): (AARCH64_GINSN_UNHANDLED_STACKOP): (AARCH64_GINSN_UNHANDLED_UNEXPECTED): (aarch64_ginsn_unhandled): (aarch64_ginsn_new): (md_assemble): * config/tc-aarch64.h (TARGET_USE_GINSN): (TARGET_USE_SCFI): (SCFI_MAX_REG_ID): (REG_FP): (REG_LR): (REG_SP): (SCFI_INIT_CFA_OFFSET): (SCFI_CALLEE_SAVED_REG_P): (aarch64_scfi_callee_saved_p):	2024-03-28 16:55:49 -07:00
Indu Bhagat	ad35d7451d	Add the tex file for the SCFI paper	2024-03-28 16:55:49 -07:00